Little novelties are part of our everyday lives, more than we usually recognize. We meet new people, hear new words, listen to new songs, and use new technologies. Although these mundane events may seem inconsequential, it is possible to argue that they share some important dynamical features with innovations, long thought to play a key role in the evolution of biological systems, human society, and technology. What novelties and innovations share is that they often do not occur by chance. Rather they seem to be triggered by some previous novelty or innovation. This has been beautifully summarized by the notion of the adjacent possible introduced by Stuart Kauffman.
Although the creative power of this expansion into the adjacent possible is widely appreciated at an anecdotal level, it remains poorly understood theoretically and undocumented empirically. In the framework of the KREYON project we are presently interested in unfolding and quantifying the underlying mechanisms through which creativity emerges and innovations diffuse, compete and stabilize. This is a timely project due to the availability of extensive longitudinal records of human, social, biological and technological evolution. The aim is to provide the scientific community with a mathematical framework to describe and investigate innovation processes and how novelties pave the way for further adjacent novelties.
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Publications
2017 |
Tani, Giulio Unveiling innovation dynamics in a web experiment on human creativity (Masters Thesis) Università La Sapienza di Roma, 2017. @mastersthesis{Tani2017, title = {Unveiling innovation dynamics in a web experiment on human creativity}, author = {Giulio Tani}, year = {2017}, date = {2017-10-31}, school = {Università La Sapienza di Roma}, abstract = {The emergence of novelties and of new trends in many different contexts ranging from arts to technology is currently a matter of interest for many studies. The availability of large crowd-sourced datasets from the web has allowed to study these dynamics in ways not possible with usual volunteer based experiments. On the other hand this kind of datasets offer little control to the researcher on which and how data are gathered. To get control over the data while keeping the advantages offered by the web, we designed and realised an experiment in the form of a web game hosted on our platform specifically built for these purposes. The game was designed to involve the players via a system of levels and rewards and allow us to collect data on how they innovate, imitate and create 2-D drawings with LEGO bricks. To gain levels players had to represent selected concepts with LEGO bricks with the possibility of taking other players? composi- tions as starting point. This experiment allowed us to gather data keeping all (or at least most part) of the influence within the experiment itself and keeping trace of most part of the interaction between players: who inspired who and, through likes and shares, how they valued compositions by other authors. We registered every action performed by the players with high temporal resolution together with every mistake or change of mind: this is a kind of information usually not available on large web datasets and yet useful to determine the dynamics. Analysing words occurrences over the 4k+ compositions and 30k+ guesses we get results in line with those kno- wn from the literature that suggests us that the dataset is self consistent. We then introduce a distance between compositions in a consistent way analysing not only shapes and colours of the compositions but also number and kind of the bricks used and proportions. This distance function was at the base of our analysis: we show the relation between creativity and influence over subsequent compositions (how they have been valued by other players), the dynamics of the emergence of novelties and how they clusterise in time. Thanks to the same distance we built an influence net- work from which we were able to derive the network characteristics such as degree distributions and clustering coefficients. The results reached so far give us the hope that even more detail of what makes a trend-setter may be unveiled with further investigation. }, keywords = {}, pubstate = {published}, tppubtype = {mastersthesis} } The emergence of novelties and of new trends in many different contexts ranging from arts to technology is currently a matter of interest for many studies. The availability of large crowd-sourced datasets from the web has allowed to study these dynamics in ways not possible with usual volunteer based experiments. On the other hand this kind of datasets offer little control to the researcher on which and how data are gathered. To get control over the data while keeping the advantages offered by the web, we designed and realised an experiment in the form of a web game hosted on our platform specifically built for these purposes. The game was designed to involve the players via a system of levels and rewards and allow us to collect data on how they innovate, imitate and create 2-D drawings with LEGO bricks. To gain levels players had to represent selected concepts with LEGO bricks with the possibility of taking other players? composi- tions as starting point. This experiment allowed us to gather data keeping all (or at least most part) of the influence within the experiment itself and keeping trace of most part of the interaction between players: who inspired who and, through likes and shares, how they valued compositions by other authors. We registered every action performed by the players with high temporal resolution together with every mistake or change of mind: this is a kind of information usually not available on large web datasets and yet useful to determine the dynamics. Analysing words occurrences over the 4k+ compositions and 30k+ guesses we get results in line with those kno- wn from the literature that suggests us that the dataset is self consistent. We then introduce a distance between compositions in a consistent way analysing not only shapes and colours of the compositions but also number and kind of the bricks used and proportions. This distance function was at the base of our analysis: we show the relation between creativity and influence over subsequent compositions (how they have been valued by other players), the dynamics of the emergence of novelties and how they clusterise in time. Thanks to the same distance we built an influence net- work from which we were able to derive the network characteristics such as degree distributions and clustering coefficients. The results reached so far give us the hope that even more detail of what makes a trend-setter may be unveiled with further investigation. |
Pullano, Giulia The dynamics of social interactions in a collective creativity experiment (Masters Thesis) Torino University , 2017. @mastersthesis{Pullano2017, title = {The dynamics of social interactions in a collective creativity experiment}, author = {Giulia Pullano}, year = {2017}, date = {2017-10-31}, school = {Torino University }, abstract = {The study of the dynamics behind the emergence of novelties and inno- vation is a relatively recent field of study in complex systems, fostered by the abundance of data about the creations and sharing of artworks and about on-line activity in general. Despite this recentness, many works have been able to discover and characterise several interesting statistical patterns related to the emergence of new creative elements and a very general mathematical framework describing the collective process of di- scovering and sharing novelties come out. However, still a lot has to be discovered concerning the conditions, either historical and social, fostering the emergence of creative elements from a group of interacting individuals. From a social perspective, many hypotheses have been developed and te- sted concerning the relations between individual like the presence of ?weak ties? in social networks or the ?folding? of different social groups into a larger one sharing a common goal. Complex Systems Science has given lit- tle contributions to the understanding of how the dynamics behind social interactions contributes to foster the emergence of creativity. This work of thesis is devoted to the analysis of data collected during a collective social experiment in which individuals were asked to collaborate in the realisation of a set of LEGO bricks sculptures. The participants to the experiments were provided with particular RFID tags, developed in the framework of the SOCIOPATTERNS project, that enabled a quite precise mapping of the social interactions occurring during their activity within the experiment. The interaction with the LEGO Sculptures were similarly mapped by means of other RFID tags placed around the sculptures, and their growth in volume has been recorded with the aid of infra-red depth sensors. The RFID sensors allowed for a reconstruction of the dynamical network of social interactions between the participants in the experiment. We looked for correlations between the evolving structure of this social net- work and the growing patterns of the sculptures, spotting the local social structures more prone for a rapid growth of the volume in small amounts of times and in long term periods. In this way, we were able to identify the social patterns more fruitful in terms of ?local consensus? around the development of the collective artwork, indicating a shared vision around the actions to be performed on it. Moreover, we were able to identify how the presence of ?influential individuals? characterised by means of information spreading models favoured the growth of the sculptures in the long-term. The novelty behind the proposed approach could contribute to shed light on the phenomena related to creativity and could be useful in conceiving and designing new collecting creativity experiments. }, keywords = {}, pubstate = {published}, tppubtype = {mastersthesis} } The study of the dynamics behind the emergence of novelties and inno- vation is a relatively recent field of study in complex systems, fostered by the abundance of data about the creations and sharing of artworks and about on-line activity in general. Despite this recentness, many works have been able to discover and characterise several interesting statistical patterns related to the emergence of new creative elements and a very general mathematical framework describing the collective process of di- scovering and sharing novelties come out. However, still a lot has to be discovered concerning the conditions, either historical and social, fostering the emergence of creative elements from a group of interacting individuals. From a social perspective, many hypotheses have been developed and te- sted concerning the relations between individual like the presence of ?weak ties? in social networks or the ?folding? of different social groups into a larger one sharing a common goal. Complex Systems Science has given lit- tle contributions to the understanding of how the dynamics behind social interactions contributes to foster the emergence of creativity. This work of thesis is devoted to the analysis of data collected during a collective social experiment in which individuals were asked to collaborate in the realisation of a set of LEGO bricks sculptures. The participants to the experiments were provided with particular RFID tags, developed in the framework of the SOCIOPATTERNS project, that enabled a quite precise mapping of the social interactions occurring during their activity within the experiment. The interaction with the LEGO Sculptures were similarly mapped by means of other RFID tags placed around the sculptures, and their growth in volume has been recorded with the aid of infra-red depth sensors. The RFID sensors allowed for a reconstruction of the dynamical network of social interactions between the participants in the experiment. We looked for correlations between the evolving structure of this social net- work and the growing patterns of the sculptures, spotting the local social structures more prone for a rapid growth of the volume in small amounts of times and in long term periods. In this way, we were able to identify the social patterns more fruitful in terms of ?local consensus? around the development of the collective artwork, indicating a shared vision around the actions to be performed on it. Moreover, we were able to identify how the presence of ?influential individuals? characterised by means of information spreading models favoured the growth of the sculptures in the long-term. The novelty behind the proposed approach could contribute to shed light on the phenomena related to creativity and could be useful in conceiving and designing new collecting creativity experiments. |
Sakellariou, Jason; Tria, Francesca; Loreto, Vittorio; Pachet, François Maximum entropy models capture melodic styles (Journal Article) Scientific Reports, 7 , 2017. @article{sakellariou2016maximum, title = {Maximum entropy models capture melodic styles}, author = { Jason Sakellariou and Francesca Tria and Vittorio Loreto and François Pachet}, editor = {Nature Publishing Group}, url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5569059/}, year = {2017}, date = {2017-01-01}, journal = {Scientific Reports}, volume = {7}, abstract = {We introduce a model for music generation where melodies are seen as a network of interacting notes. Starting from the principle of maximum entropy we assign to this network a probability distribution, which is learned from an existing musical corpus. We use this model to generate novel musical sequences that mimic the style of the corpus. Our main result is that this model can reproduce high-order patterns despite having a polynomial sample complexity. This is in contrast with the more traditionally used Markov models that have an exponential sample complexity.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We introduce a model for music generation where melodies are seen as a network of interacting notes. Starting from the principle of maximum entropy we assign to this network a probability distribution, which is learned from an existing musical corpus. We use this model to generate novel musical sequences that mimic the style of the corpus. Our main result is that this model can reproduce high-order patterns despite having a polynomial sample complexity. This is in contrast with the more traditionally used Markov models that have an exponential sample complexity. |
Monechi, Bernardo; Gravino, Pietro; Clemente, Riccardo Di Trainstopping: modelling delays dynamics on railways networks (Journal Article) submitted for publication to EPJ Data Science (2017), 2017. @article{Monechi2017, title = {Trainstopping: modelling delays dynamics on railways networks}, author = {Bernardo Monechi and Pietro Gravino and Riccardo Di Clemente}, url = {https://arxiv.org/abs/1707.08632}, year = {2017}, date = {2017-01-01}, journal = {submitted for publication to EPJ Data Science (2017)}, abstract = {Railways are a key infrastructure for any modern country, so that their state of development has even been used as a significant indicator of a country’s economic advancement. Moreover, their importance has been growing in the last decades either because of the growing Railway Traffic and to governments investments, aiming at exploiting railways means to reduce CO2 emissions and hence global warming. To the present day, many extreme events (i.e. major disruptions and large delays compromising the correct functioning of the system) occurs on a daily basis. However these phenomena have been approached, so far, from a transportation engineering point of view while a general theoretical understanding is still lacking. A better comprehension of these critical situation from a theoretical point of view could be undoubtedly useful in order to improve traffic handling policies. In this work we move toward this comprehension by proposing a model about train dynamics on railways network aiming to unveil how delays spawn and spread among the network. Inspired by models for epidemic spreading, we model the diffusion of delays among train as the diffusion of a contagion among a population of moving individuals. We built and tested our model using two large dataset about Italian and German railway traffic, collected using APIs intended to give passengers information about the trains, the state of the service and train delays. The model reproduces adequately delays dynamics in both systems, meaning that it captures the underlying key factors. In particular, our model predicts that the insurgence of clusters of stations with large delays is not due to external factors, but mainly to the interaction between different trains. Also, through our model is capable to give a quantitative account of the difference between the two considered railway systems in terms of probability of contagion and delays dynamics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Railways are a key infrastructure for any modern country, so that their state of development has even been used as a significant indicator of a country’s economic advancement. Moreover, their importance has been growing in the last decades either because of the growing Railway Traffic and to governments investments, aiming at exploiting railways means to reduce CO2 emissions and hence global warming. To the present day, many extreme events (i.e. major disruptions and large delays compromising the correct functioning of the system) occurs on a daily basis. However these phenomena have been approached, so far, from a transportation engineering point of view while a general theoretical understanding is still lacking. A better comprehension of these critical situation from a theoretical point of view could be undoubtedly useful in order to improve traffic handling policies. In this work we move toward this comprehension by proposing a model about train dynamics on railways network aiming to unveil how delays spawn and spread among the network. Inspired by models for epidemic spreading, we model the diffusion of delays among train as the diffusion of a contagion among a population of moving individuals. We built and tested our model using two large dataset about Italian and German railway traffic, collected using APIs intended to give passengers information about the trains, the state of the service and train delays. The model reproduces adequately delays dynamics in both systems, meaning that it captures the underlying key factors. In particular, our model predicts that the insurgence of clusters of stations with large delays is not due to external factors, but mainly to the interaction between different trains. Also, through our model is capable to give a quantitative account of the difference between the two considered railway systems in terms of probability of contagion and delays dynamics. |
Cuskley, Christine; Castellano, Claudio; Colaiori, Francesca; Loreto, Vittorio; Pugliese, Martina; Tria, Francesca The regularity game: Investigating linguistic rule dynamics in a population of interacting agents (Journal Article) Cognition, 159 , pp. 25–32, 2017. @article{cuskley2017regularity, title = {The regularity game: Investigating linguistic rule dynamics in a population of interacting agents}, author = { Christine Cuskley and Claudio Castellano and Francesca Colaiori and Vittorio Loreto and Martina Pugliese and Francesca Tria}, url = {http://www.sciencedirect.com/science/article/pii/S0010027716302670}, year = {2017}, date = {2017-01-01}, journal = {Cognition}, volume = {159}, pages = {25--32}, publisher = {Elsevier}, abstract = {Rules are an efficient feature of natural languages which allow speakers to use a finite set of instructions to generate a virtually infinite set of utterances. Yet, for many regular rules, there are irregular exceptions. There has been lively debate in cognitive science about how individual learners acquire rules and exceptions; for example, how they learn the past tense of preach is preached, but for teach it is taught. However, for most population or language-level models of language structure, particularly from the perspective of language evolution, the goal has generally been to examine how languages evolve stable structure, and neglects the fact that in many cases, languages exhibit exceptions to structural rules. We examine the dynamics of regularity and irregularity across a population of interacting agents to investigate how, for example, the irregular teach coexists beside the regular preach in a dynamic language system. Models show that in the absence of individual biases towards either regularity or irregularity, the outcome of a system is determined entirely by the initial condition. On the other hand, in the presence of individual biases, rule systems exhibit frequency dependent patterns in regularity reminiscent of patterns found in natural language. We implement individual biases towards regularity in two ways: through ?child? agents who have a preference to generalise using the regular form, and through a memory constraint wherein an agent can only remember an irregular form for a finite time period. We provide theoretical arguments for the prediction of a critical frequency below which irregularity cannot persist in terms of the duration of the finite time period which constrains agent memory. Further, within our framework we also find stable irregularity, arguably a feature of most natural languages not accounted for in many other cultural models of language structure.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Rules are an efficient feature of natural languages which allow speakers to use a finite set of instructions to generate a virtually infinite set of utterances. Yet, for many regular rules, there are irregular exceptions. There has been lively debate in cognitive science about how individual learners acquire rules and exceptions; for example, how they learn the past tense of preach is preached, but for teach it is taught. However, for most population or language-level models of language structure, particularly from the perspective of language evolution, the goal has generally been to examine how languages evolve stable structure, and neglects the fact that in many cases, languages exhibit exceptions to structural rules. We examine the dynamics of regularity and irregularity across a population of interacting agents to investigate how, for example, the irregular teach coexists beside the regular preach in a dynamic language system. Models show that in the absence of individual biases towards either regularity or irregularity, the outcome of a system is determined entirely by the initial condition. On the other hand, in the presence of individual biases, rule systems exhibit frequency dependent patterns in regularity reminiscent of patterns found in natural language. We implement individual biases towards regularity in two ways: through ?child? agents who have a preference to generalise using the regular form, and through a memory constraint wherein an agent can only remember an irregular form for a finite time period. We provide theoretical arguments for the prediction of a critical frequency below which irregularity cannot persist in terms of the duration of the finite time period which constrains agent memory. Further, within our framework we also find stable irregularity, arguably a feature of most natural languages not accounted for in many other cultural models of language structure. |
Rodi, Giovanna Chiara; Loreto, Vittorio; Tria, Francesca Search strategies of Wikipedia readers (Journal Article) PLOS ONE, 12 (2), pp. e0170746, 2017. @article{rodi2017search, title = {Search strategies of Wikipedia readers}, author = { Giovanna Chiara Rodi and Vittorio Loreto and Francesca Tria}, url = {http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0170746}, year = {2017}, date = {2017-01-01}, journal = {PLOS ONE}, volume = {12}, number = {2}, pages = {e0170746}, publisher = {Public Library of Science}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
, (Ed.) Copystree: gaming artificial phylogenies (Periodical) Capturing Phylogenetic Algorithms for Linguistics, 2017. @periodical{Pompei2017, title = {Copystree: gaming artificial phylogenies}, author = {Simone Pompei and Vittorio Loreto and Francesca Tria}, url = {http://www.socialdynamics.it/pubs/}, year = {2017}, date = {2017-01-01}, issuetitle = {Capturing Phylogenetic Algorithms for Linguistics}, journal = {Language Dynamics and Change}, abstract = {The reconstruction of phylogenies of cultural artefacts represents an open problem that mixes theoretical and computational challenges. Existing bench- marks rely on simulated phylogenies, where hypotheses on the underlying evolutionary mechanisms are unavoidable, or in real data phylogenies, for which no true evolutionary history is known. Here we introduce a web-based game, Copystree, where users create phylogenies of manuscripts, through successive copying actions, in a fully monitored setup. While players enjoy the experience, Copystree allows to build artificial phylogenies whose evolutionary processes do not obey to any pre-defined theoretical mechanisms, being generated instead with the unpredictability of human creativity. We present the analysis of the data gathered during the first set of experiments and use the artificial phylogenies gathered for a first test of existing phylogenetic algorithms.}, keywords = {}, pubstate = {published}, tppubtype = {periodical} } The reconstruction of phylogenies of cultural artefacts represents an open problem that mixes theoretical and computational challenges. Existing bench- marks rely on simulated phylogenies, where hypotheses on the underlying evolutionary mechanisms are unavoidable, or in real data phylogenies, for which no true evolutionary history is known. Here we introduce a web-based game, Copystree, where users create phylogenies of manuscripts, through successive copying actions, in a fully monitored setup. While players enjoy the experience, Copystree allows to build artificial phylogenies whose evolutionary processes do not obey to any pre-defined theoretical mechanisms, being generated instead with the unpredictability of human creativity. We present the analysis of the data gathered during the first set of experiments and use the artificial phylogenies gathered for a first test of existing phylogenetic algorithms. |
2016 |
Thurner, Stefan 43 Visions for Complexity (Exploring Complexity) (Book) WSPC, 2016, ISBN: 978-981-3206-84-7. @book{Thurner2016, title = {43 Visions for Complexity (Exploring Complexity)}, author = {Stefan Thurner}, url = {http://www.worldscientific.com/worldscibooks/10.1142/10360 https://www.amazon.com/43-Visions-Complexity-Exploring-ebook/dp/B01N3XIXCN}, isbn = {978-981-3206-84-7}, year = {2016}, date = {2016-11-04}, volume = {1}, publisher = {WSPC}, abstract = {Coping with the complexities of the social world in the 21st century requires deeper quantitative and predictive understanding. Forty-three internationally acclaimed scientists and thinkers share their vision for complexity science in the next decade in this invaluable book. Topics cover how complexity and big data science could help society to tackle the great challenges ahead, and how the newly established Complexity Science Hub Vienna might be a facilitator on this path.}, keywords = {}, pubstate = {published}, tppubtype = {book} } Coping with the complexities of the social world in the 21st century requires deeper quantitative and predictive understanding. Forty-three internationally acclaimed scientists and thinkers share their vision for complexity science in the next decade in this invaluable book. Topics cover how complexity and big data science could help society to tackle the great challenges ahead, and how the newly established Complexity Science Hub Vienna might be a facilitator on this path. |
V Loreto VDP Servedio, SH Strogatz Tria Dynamics on Expanding Spaces: Modeling the Emergence of Novelties (Book Chapter) Mirko Degli Esposti Eduardo G. Altmann, François Pachet (Ed.): Creativity and Universality in Language, pp. 59-83, Springer International Publishing, 2016, ISBN: 978-3-319-24401-3. @inbook{Loreto2016, title = {Dynamics on Expanding Spaces: Modeling the Emergence of Novelties}, author = {V Loreto, VDP Servedio, SH Strogatz, F Tria}, editor = {Mirko Degli Esposti, Eduardo G. Altmann, François Pachet}, url = {http://link.springer.com/chapter/10.1007%2F978-3-319-24403-7_5}, doi = {10.1007/978-3-319-24403-7_5}, isbn = {978-3-319-24401-3}, year = {2016}, date = {2016-05-19}, booktitle = {Creativity and Universality in Language}, pages = {59-83}, publisher = {Springer International Publishing}, series = {Lecture Notes in Morphogenesis}, abstract = {Novelties are part of our daily lives. We constantly adopt new technologies, conceive new ideas, meet new people, and experiment with new situations. Occasionally, we as individual, in a complicated cognitive and sometimes fortuitous process, come up with something that is not only new to us, but to our entire society so that what is a personal novelty can turn into an innovation at a global level. Innovations occur throughout social, biological, and technological systems and, though we perceive them as a very natural ingredient of our human experience, little is known about the processes determining their emergence. Still the statistical occurrence of innovations shows striking regularities that represent a starting point to get a deeper insight in the whole phenomenology. This paper represents a small step in that direction, focusing on reviewing the scientific attempts to effectively model the emergence of the new and its regularities, with an emphasis on more recent contributions: from the plain Simon’s model tracing back to the 1950s, to the newest model of Polya’s urn with triggering of one novelty by another. What seems to be key in the successful modeling schemes proposed so far is the idea of looking at evolution as a path in a complex space, physical, conceptual, biological, and technological, whose structure and topology get continuously reshaped and expanded by the occurrence of the new. Mathematically, it is very interesting to look at the consequences of the interplay between the “actual” and the “possible” and this is the aim of this short review.}, keywords = {}, pubstate = {published}, tppubtype = {inbook} } Novelties are part of our daily lives. We constantly adopt new technologies, conceive new ideas, meet new people, and experiment with new situations. Occasionally, we as individual, in a complicated cognitive and sometimes fortuitous process, come up with something that is not only new to us, but to our entire society so that what is a personal novelty can turn into an innovation at a global level. Innovations occur throughout social, biological, and technological systems and, though we perceive them as a very natural ingredient of our human experience, little is known about the processes determining their emergence. Still the statistical occurrence of innovations shows striking regularities that represent a starting point to get a deeper insight in the whole phenomenology. This paper represents a small step in that direction, focusing on reviewing the scientific attempts to effectively model the emergence of the new and its regularities, with an emphasis on more recent contributions: from the plain Simon’s model tracing back to the 1950s, to the newest model of Polya’s urn with triggering of one novelty by another. What seems to be key in the successful modeling schemes proposed so far is the idea of looking at evolution as a path in a complex space, physical, conceptual, biological, and technological, whose structure and topology get continuously reshaped and expanded by the occurrence of the new. Mathematically, it is very interesting to look at the consequences of the interplay between the “actual” and the “possible” and this is the aim of this short review. |
Mastroianni, Pierpaolo; Monechi, Bernardo; Servedio, Vito DP; Liberto, Carlo; Valenti, Gaetano; Loreto, Vittorio Individual Mobility Patterns in Urban Environment (Inproceeding) e COMPLEXIS 2016, 1st International Conference on Complex Information Systems, Rome, 22-24 April 2016, 2016. @inproceedings{Mastroianni2016, title = {Individual Mobility Patterns in Urban Environment}, author = {Pierpaolo Mastroianni and Bernardo Monechi and Vito DP Servedio and Carlo Liberto and Gaetano Valenti and Vittorio Loreto}, url = {https://www.researchgate.net/profile/Bernardo_Monechi/publication/302973966_Individual_Mobility_Patterns_in_Urban_Environment/links/57c4454808aee50192e89a98.pdf}, year = {2016}, date = {2016-04-22}, booktitle = {e COMPLEXIS 2016, 1st International Conference on Complex Information Systems, Rome, 22-24 April 2016}, abstract = {The understanding and the characterisation of individual mobility patterns in urban environments is important in order to improve liveability and planning of big cities. In relatively recent times, the availability of data regarding human movements have fostered the emergence of a new branch of social studies, with the aim to unveil and study those patterns thanks to data collected by means of geolocalisation technologies. In this paper we analyse a large dataset of GPS tracks of cars collected in Rome (Italy). Dividing the drivers in classes according to the number of trips they perform in a day, we show that the sequence of the travelled space connecting two consecutive stops shows a precise behaviour so that the shortest trips are performed at the middle of the sequence, when the longest occur at the beginning and at the end when drivers head back home. We show that this behaviour is consistent with the idea of an optimisation process in which the total travel time is minimised, under the effect of spatial constraints so that the starting points is on the border of the space in which the dynamics takes place.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } The understanding and the characterisation of individual mobility patterns in urban environments is important in order to improve liveability and planning of big cities. In relatively recent times, the availability of data regarding human movements have fostered the emergence of a new branch of social studies, with the aim to unveil and study those patterns thanks to data collected by means of geolocalisation technologies. In this paper we analyse a large dataset of GPS tracks of cars collected in Rome (Italy). Dividing the drivers in classes according to the number of trips they perform in a day, we show that the sequence of the travelled space connecting two consecutive stops shows a precise behaviour so that the shortest trips are performed at the middle of the sequence, when the longest occur at the beginning and at the end when drivers head back home. We show that this behaviour is consistent with the idea of an optimisation process in which the total travel time is minimised, under the effect of spatial constraints so that the starting points is on the border of the space in which the dynamics takes place. |
Gravino, Pietro; Caminiti, Saverio; Sirbu, Alina; Tria, Francesca; Servedio, Vito; Loreto, Vittorio Unveiling political opinion structures with a web-experiment (Inproceeding) COMPLEXIS 2016, 1st International Conference on Complex Information Systems, Rome, 22-24 April 2016, 2016. @inproceedings{Gravino2016b, title = {Unveiling political opinion structures with a web-experiment}, author = {Pietro Gravino and Saverio Caminiti and Alina Sirbu and Francesca Tria and Vito D. P. Servedio and Vittorio Loreto}, url = {http://www.scitepress.org/DigitalLibrary/Link.aspx?doi=10.5220/0005906300390047}, year = {2016}, date = {2016-04-22}, booktitle = {COMPLEXIS 2016, 1st International Conference on Complex Information Systems, Rome, 22-24 April 2016}, abstract = {The dynamics of political votes has been widely studied, both for its practical interest and as a paradigm of the dynamics of mass opinions and collective phenomena, where theoretical predictions can be easily tested. However, the vote outcome is often influenced by many factors beyond the bare opinion on the candidate, and in most cases it is bound to a single preference. The voter perception of the political space is still to be elucidated. We here propose a web experiment (laPENSOcos`ı) where we explicitly investigate participants’ opinions on political entities (parties, coalitions, individual candidates) of the Italian political scene. As a main result, we show that the political perception follows a Weber-Fechner-like law, i.e., when ranking political entities according to the user expressed preferences, the perceived distance of the user from a given entity scales as the logarithm of this rank.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } The dynamics of political votes has been widely studied, both for its practical interest and as a paradigm of the dynamics of mass opinions and collective phenomena, where theoretical predictions can be easily tested. However, the vote outcome is often influenced by many factors beyond the bare opinion on the candidate, and in most cases it is bound to a single preference. The voter perception of the political space is still to be elucidated. We here propose a web experiment (laPENSOcos`ı) where we explicitly investigate participants’ opinions on political entities (parties, coalitions, individual candidates) of the Italian political scene. As a main result, we show that the political perception follows a Weber-Fechner-like law, i.e., when ranking political entities according to the user expressed preferences, the perceived distance of the user from a given entity scales as the logarithm of this rank. |
Monechi, Bernardo; Ruiz-Serrano, Alvaro; Tria, Francesca; Loreto, Vittorio Waves of Novelties in the Expansion into the Adjacent Possible (Journal Article) PloS one, 12 (6), pp. e0179303, 2016. @article{Monechi2016, title = {Waves of Novelties in the Expansion into the Adjacent Possible}, author = {Bernardo Monechi and Alvaro Ruiz-Serrano and Francesca Tria and Vittorio Loreto }, editor = {Public Library of Science}, url = {http://www.socialdynamics.it/pubs/}, year = {2016}, date = {2016-03-21}, journal = {PloS one}, volume = {12}, number = {6}, pages = {e0179303}, abstract = {The emergence of novelties and their rise and fall in popularity is an ubiquitous phenomenon in human activities. The coexistence of always popular milestones with novel and sometimes ephemeral trends pervades technological, scientific and artistic production. By introducing suitable statistical measures, we demonstrate that different systems of human activities, i.e. the creation of hashtags in Twitter, the interaction with online program code repositories, the creation of texts and the listening of songs on an on-line platform, exhibit surprisingly similar properties. We then introduce a general framework to explain those regularities. We propose a simple mathematical model based on the expansion into the adjacent possible, that has been proven to be a very general and powerful mechanism able to explain many of the statistical patterns emerging in innovation dynamics, to which we add two crucial elements. On the one hand we quantify the idea that, while exploring a conceptual or physical space, inertia exists towards known already discovered elements. On the other hand, we highlight the role of the collective dynamics - where many users interact, in a direct or indirect way in the emergence and diffusion of novelties and innovations. }, keywords = {}, pubstate = {published}, tppubtype = {article} } The emergence of novelties and their rise and fall in popularity is an ubiquitous phenomenon in human activities. The coexistence of always popular milestones with novel and sometimes ephemeral trends pervades technological, scientific and artistic production. By introducing suitable statistical measures, we demonstrate that different systems of human activities, i.e. the creation of hashtags in Twitter, the interaction with online program code repositories, the creation of texts and the listening of songs on an on-line platform, exhibit surprisingly similar properties. We then introduce a general framework to explain those regularities. We propose a simple mathematical model based on the expansion into the adjacent possible, that has been proven to be a very general and powerful mechanism able to explain many of the statistical patterns emerging in innovation dynamics, to which we add two crucial elements. On the one hand we quantify the idea that, while exploring a conceptual or physical space, inertia exists towards known already discovered elements. On the other hand, we highlight the role of the collective dynamics - where many users interact, in a direct or indirect way in the emergence and diffusion of novelties and innovations. |
Gravino, Pietro; Monechi, Bernardo; Servedio, Vito DP; Tria, Francesca; Loreto, Vittorio Crossing the horizon: exploring the adjacent possible in a cultural system (Proceeding) Proceedings of the Seventh International Conference on Computational Creativity, June 2016, 2016. @proceedings{Gravino2016, title = {Crossing the horizon: exploring the adjacent possible in a cultural system}, author = {Pietro Gravino and Bernardo Monechi and Vito DP Servedio and Francesca Tria and Vittorio Loreto}, url = {http://www.computationalcreativity.net/iccc2016/wp-content/uploads/2016/01/Crossing-the-horizon.pdf}, year = {2016}, date = {2016-03-05}, journal = {submitted to "ICCC 2016 - The Seventh International Conference on Computational Creativity"}, publisher = {Proceedings of the Seventh International Conference on Computational Creativity, June 2016}, abstract = {It is common opinion that many innovations are triggered by serendipity whose notion is associated with fortuitous events leading to unintended consequences. One might argue that this interpretation is due to the poor understanding of the dynamics of innovations. Very little is known, in fact, about how innovations proceed and samples the space of potential novelties. This space is usually referred to as the adjacent possible, a concept originally introduced in the study of biological systems to indicate the set of possibilities that are one step away from what actually exists. In this paper we focus on the problem of defining the adjacent possible space, and analyzing its dynamics, for a particular system, namely the cultural system of the network of movies. We synthesized to this end the graph emerging from the Internet Movies Database (IMDb) and looked at the static and dynamical properties of this network. We deal, in particular, with the subtle mechanism of the adjacent possible by measuring the expansion and the coverage of this elusive space during the global evolution of the system. Finally, we introduce the concept of adjacent possibilities at the level of single node and try to elucidate its nature by looking at the correlations with topological and user annotation metrics.}, keywords = {}, pubstate = {published}, tppubtype = {proceedings} } It is common opinion that many innovations are triggered by serendipity whose notion is associated with fortuitous events leading to unintended consequences. One might argue that this interpretation is due to the poor understanding of the dynamics of innovations. Very little is known, in fact, about how innovations proceed and samples the space of potential novelties. This space is usually referred to as the adjacent possible, a concept originally introduced in the study of biological systems to indicate the set of possibilities that are one step away from what actually exists. In this paper we focus on the problem of defining the adjacent possible space, and analyzing its dynamics, for a particular system, namely the cultural system of the network of movies. We synthesized to this end the graph emerging from the Internet Movies Database (IMDb) and looked at the static and dynamical properties of this network. We deal, in particular, with the subtle mechanism of the adjacent possible by measuring the expansion and the coverage of this elusive space during the global evolution of the system. Finally, we introduce the concept of adjacent possibilities at the level of single node and try to elucidate its nature by looking at the correlations with topological and user annotation metrics. |
Monechi, Bernardo; Gravino, Pietro; Servedio, Vito DP; Tria, Francesca; Loreto, Vittorio Significance and Popularity in Music Production Paper (Journal Article) Open Science, 4 (7), pp. 170433, 2016. @article{Monechi2016, title = {Significance and Popularity in Music Production Paper}, author = {Bernardo Monechi and Pietro Gravino and Vito DP Servedio and Francesca Tria and Vittorio Loreto }, editor = {The Royal Society}, url = {http://xtribe.eu/sites/default/files/kreyon_files/Significance_and_Popularity_in_Music_Production.pdf}, year = {2016}, date = {2016-03-05}, journal = {Open Science}, volume = {4}, number = {7}, pages = {170433}, publisher = {submitted to PLoS ONE}, abstract = {In the world of creative productions there is a constant struggle to achieve fame and popularity. While highly popular creations are usually well remembered throughout the years, many influential works that did not achieve that status are long-forgotten. Due to their relevance for the whole artistic production, it is important to identify them and save their memory for obvious cultural reasons. In this paper we focus on the musical context and we analyze the dynamics of the tagging process on Last.fm, an on-line catalog of music albums. We define a set of general metrics aiming at characterizing the creative potential and the long-term significance of creative products and we apply them to the case of musical albums. We then adopt these metrics to implement an automated prediction method of both the commercial success of a creation and its belonging to expert validated lists of particularly creative and important works. We show that our metrics are not only useful to asses such predictions, but can also highlight important differences between culturally relevant and simply popular products of human creative production.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In the world of creative productions there is a constant struggle to achieve fame and popularity. While highly popular creations are usually well remembered throughout the years, many influential works that did not achieve that status are long-forgotten. Due to their relevance for the whole artistic production, it is important to identify them and save their memory for obvious cultural reasons. In this paper we focus on the musical context and we analyze the dynamics of the tagging process on Last.fm, an on-line catalog of music albums. We define a set of general metrics aiming at characterizing the creative potential and the long-term significance of creative products and we apply them to the case of musical albums. We then adopt these metrics to implement an automated prediction method of both the commercial success of a creation and its belonging to expert validated lists of particularly creative and important works. We show that our metrics are not only useful to asses such predictions, but can also highlight important differences between culturally relevant and simply popular products of human creative production. |
Tria, Francesca; Loreto, Vittorio; Servedio, Vito; Salikoko, Mufwene Modeling The Emergence Of Creole Languages (Inproceeding) Roberts,; Cuskley,; McCrohon,; Barceló-Coblijn,; Fehér,; Verhoef, (Ed.): The Evolution of Language: Proceedings of the 11th International Conference (EVOLANGX11), 2016. @inproceedings{evolang11_89, title = {Modeling The Emergence Of Creole Languages}, author = { Francesca Tria and Vittorio Loreto and Vito Servedio and S. Mufwene Salikoko}, editor = {S.G. Roberts and C. Cuskley and L. McCrohon and L. Barceló-Coblijn and O. Fehér and T. Verhoef}, url = {http://evolang.org/neworleans/papers/89.html}, year = {2016}, date = {2016-01-01}, booktitle = {The Evolution of Language: Proceedings of the 11th International Conference (EVOLANGX11)}, abstract = {Creole languages offer an invaluable opportunity to study the processes leading to the emergence and evolution of Language, thanks to the short - typically a few generations - and reasonably well defined time-scales involved in their emergence. Another well-known case of a very fast emergence of a Language, though referring to a much smaller population size and different ecological conditions, is that of the Nicaraguan Sign Language. What these two phenomena have in common is that in both cases what is emerging is a contact language, i.e., a language born out of the non-trivial interaction of two (or more) parent languages. This is a typical case of what is known in biology as horizontal transmission. In many well-documented cases, creoles emerged in large segregated sugarcane or rice plantations on which the slave labourers were the overwhelming majority. Lacking a common substrate language, slaves were naturally brought to shift to the economically and politically dominant European language (often referred to as the lexifier) to bootstrap an effective communication system among themselves. Here, we focus on the emergence of creole languages originated in the contacts of European colonists and slaves during the 17th and 18th centuries in exogenous plantation colonies of especially the Atlantic and Indian Ocean, where detailed census data are available. Those for several States of USA can be found at http://www.census.gov/history, while for Central America and the Caribbean can be found at http://www.jamaicanfamilysearch.com/Samples/1790al11.htm. Without entering in the details of the creole formation at a fine-grained linguistic level, we aim at uncovering some of the general mechanisms that determine the emergence of contact languages, and that successfully apply to the case of creole formation.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Creole languages offer an invaluable opportunity to study the processes leading to the emergence and evolution of Language, thanks to the short - typically a few generations - and reasonably well defined time-scales involved in their emergence. Another well-known case of a very fast emergence of a Language, though referring to a much smaller population size and different ecological conditions, is that of the Nicaraguan Sign Language. What these two phenomena have in common is that in both cases what is emerging is a contact language, i.e., a language born out of the non-trivial interaction of two (or more) parent languages. This is a typical case of what is known in biology as horizontal transmission. In many well-documented cases, creoles emerged in large segregated sugarcane or rice plantations on which the slave labourers were the overwhelming majority. Lacking a common substrate language, slaves were naturally brought to shift to the economically and politically dominant European language (often referred to as the lexifier) to bootstrap an effective communication system among themselves. Here, we focus on the emergence of creole languages originated in the contacts of European colonists and slaves during the 17th and 18th centuries in exogenous plantation colonies of especially the Atlantic and Indian Ocean, where detailed census data are available. Those for several States of USA can be found at http://www.census.gov/history, while for Central America and the Caribbean can be found at http://www.jamaicanfamilysearch.com/Samples/1790al11.htm. Without entering in the details of the creole formation at a fine-grained linguistic level, we aim at uncovering some of the general mechanisms that determine the emergence of contact languages, and that successfully apply to the case of creole formation. |
Cuskley, Christine; Loreto, Vittorio The Emergence Of Rules And Exceptions In A Population Of Interacting Agents (Inproceeding) Roberts,; Cuskley,; McCrohon,; Barceló-Coblijn,; Fehér,; Verhoef, (Ed.): The Evolution of Language: Proceedings of the 11th International Conference (EVOLANGX11), 2016. @inproceedings{evolang11_119, title = {The Emergence Of Rules And Exceptions In A Population Of Interacting Agents}, author = { Christine Cuskley and Vittorio Loreto}, editor = {S.G. Roberts and C. Cuskley and L. McCrohon and L. Barceló-Coblijn and O. Fehér and T. Verhoef}, url = {http://evolang.org/neworleans/papers/119.html}, year = {2016}, date = {2016-01-01}, booktitle = {The Evolution of Language: Proceedings of the 11th International Conference (EVOLANGX11)}, abstract = {Rules are an efficient feature of natural languages which allow speakers to use a finite set of instructions to generate a virtually infinite set of utterances. Yet, for many regular rules, there are irregular exceptions. There has been lively debate in cognitive science about how individual learners acquire rules and exceptions; for example, how they learn the past tense of preach is preached, but for teach it is taught. In this paper, we take a different perspective, examining the dynamics of regularity and irregularity across a population of interacting agents to investigate how inflectional rules are applied to verbs. We show that in the absence of biases towards either regularity or irregularity, the outcome is determined by the initial condition, irrespective of the frequency of usage of the given lemma. On the other hand, in presence of biases, rule systems exhibit frequency dependent patterns in regularity reminiscent of patterns in natural language corpora. We examine the case where individuals are biased towards linguistic regularity in two ways: either as child learners, or through a memory constraint wherein irregular forms can only be remembered by an individual agent for a finite time period. We provide theoretical arguments for the prediction of a critical frequency below which irregularity cannot persist in terms of the duration of the finite time period which constrains agent memory.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Rules are an efficient feature of natural languages which allow speakers to use a finite set of instructions to generate a virtually infinite set of utterances. Yet, for many regular rules, there are irregular exceptions. There has been lively debate in cognitive science about how individual learners acquire rules and exceptions; for example, how they learn the past tense of preach is preached, but for teach it is taught. In this paper, we take a different perspective, examining the dynamics of regularity and irregularity across a population of interacting agents to investigate how inflectional rules are applied to verbs. We show that in the absence of biases towards either regularity or irregularity, the outcome is determined by the initial condition, irrespective of the frequency of usage of the given lemma. On the other hand, in presence of biases, rule systems exhibit frequency dependent patterns in regularity reminiscent of patterns in natural language corpora. We examine the case where individuals are biased towards linguistic regularity in two ways: either as child learners, or through a memory constraint wherein irregular forms can only be remembered by an individual agent for a finite time period. We provide theoretical arguments for the prediction of a critical frequency below which irregularity cannot persist in terms of the duration of the finite time period which constrains agent memory. |
Gelardi, Valeria Analysis of the Structure and the Collaborative Dynamics of GitHub Projects (Masters Thesis) Undergraduate thesis at Torino University, 2016. @mastersthesis{Gelardi2016, title = {Analysis of the Structure and the Collaborative Dynamics of GitHub Projects}, author = {Valeria Gelardi}, url = {http://www.socialdynamics.it/pubs/}, year = {2016}, date = {2016-01-01}, school = {Undergraduate thesis at Torino University}, abstract = {The recent spread of social networks and ICT systems has allowed for a huge availability of data on social phenomena and collective behaviour. This has induced a deep change in social dynamics field, that moved from an essentially theoretical approach to a strongly data driven one. In such framework, the present work aims at exploring the collaboration dynamics and the organisational structures within the GitHub platform. Moreover, the purpose is using success and popularity as feedbacks to check whether some particular structures exist that are associated with more efficiency, better results and subsequently more innovative features in the development of the code. GitHub is based on the Git revision control system and is currently the most important platform for open source coding, counting millions of repositories and active users. Moreover, the complete timeline of GitHub activity is publicly accessible on the GitHub Archive website. GitHub is therefore a particularly suitable system to observe and analyse collective social behaviours and collaborative dynamics. The collaboration among users fosters an uninterrupted flow of new ideas which actualise in many different events such as the creation of new projects and updating of existing ones through code modifications. The analysis required a preliminary selection of the data downloaded from GitHub Archive in order to create a database containing all the necessary information about projects activity. The analysis carried out on this database was mostly inspired by previous research on innovation dynamics in the framework of complex systems. Every project was mapped in a network structure in order to observe dynamically the development and the modifications of the code. Some metrics were defined that could estimate the collaboration degree among users and the organization of the workload within the developing branches. Other metrics were chosen in order to evaluate both the success and the popularity reached by a project and its potential innovation. Correlation analysis between the metrics and the indexes above mentioned allow for some evaluations about the interdependence between attention received and structural features of the projects. This thesis work follows up several quantitative analyses on GitHub presented in literature and proposes a new visualisation of internal structures and collaborative dynamics within GitHub projects. Moreover, identifying successful patterns could help in highlighting the most influential and pioneering projects and encouraging their development.}, keywords = {}, pubstate = {published}, tppubtype = {mastersthesis} } The recent spread of social networks and ICT systems has allowed for a huge availability of data on social phenomena and collective behaviour. This has induced a deep change in social dynamics field, that moved from an essentially theoretical approach to a strongly data driven one. In such framework, the present work aims at exploring the collaboration dynamics and the organisational structures within the GitHub platform. Moreover, the purpose is using success and popularity as feedbacks to check whether some particular structures exist that are associated with more efficiency, better results and subsequently more innovative features in the development of the code. GitHub is based on the Git revision control system and is currently the most important platform for open source coding, counting millions of repositories and active users. Moreover, the complete timeline of GitHub activity is publicly accessible on the GitHub Archive website. GitHub is therefore a particularly suitable system to observe and analyse collective social behaviours and collaborative dynamics. The collaboration among users fosters an uninterrupted flow of new ideas which actualise in many different events such as the creation of new projects and updating of existing ones through code modifications. The analysis required a preliminary selection of the data downloaded from GitHub Archive in order to create a database containing all the necessary information about projects activity. The analysis carried out on this database was mostly inspired by previous research on innovation dynamics in the framework of complex systems. Every project was mapped in a network structure in order to observe dynamically the development and the modifications of the code. Some metrics were defined that could estimate the collaboration degree among users and the organization of the workload within the developing branches. Other metrics were chosen in order to evaluate both the success and the popularity reached by a project and its potential innovation. Correlation analysis between the metrics and the indexes above mentioned allow for some evaluations about the interdependence between attention received and structural features of the projects. This thesis work follows up several quantitative analyses on GitHub presented in literature and proposes a new visualisation of internal structures and collaborative dynamics within GitHub projects. Moreover, identifying successful patterns could help in highlighting the most influential and pioneering projects and encouraging their development. |
Pugliese, Martina; Loreto, Vittorio; Pompei, Simone; Tria, Francesca Exploring the evolution of pathogens organised in discrete antigenic clusters (Journal Article) Journal of Statistical Mechanics: Theory and Experiment, 2016 (9), pp. 093306, 2016. @article{pugliese2016exploring, title = {Exploring the evolution of pathogens organised in discrete antigenic clusters}, author = { Martina Pugliese and Vittorio Loreto and Simone Pompei and Francesca Tria}, url = {http://iopscience.iop.org/article/10.1088/1742-5468/2016/09/093306/meta}, year = {2016}, date = {2016-01-01}, journal = {Journal of Statistical Mechanics: Theory and Experiment}, volume = {2016}, number = {9}, pages = {093306}, publisher = {IOP Publishing}, abstract = {We present a numerical model for the evolution of pathogens organised in discrete antigenic clusters, where individuals in the same clusters have the same fitness. The fitness of each cluster is a decreasing function of the total number of cluster members appeared in the population. Cluster transition is modelled with inclusion and exclusion of dynamical epistatic effects. In both cases we observe a continuous transition, driven by the mutation rate, from a dynamics with single clusters alternating in time to the coexistence of many clusters in the population. The transition between the two regimes is investigated in terms of the key parameters of the model. We find that the location and the scaling of this transition can be explained in terms of the time of first appearance of a new cluster in the population. The presence of dynamical epistatic effects results in a shift of the value of the mutation rate where the transition occurs.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We present a numerical model for the evolution of pathogens organised in discrete antigenic clusters, where individuals in the same clusters have the same fitness. The fitness of each cluster is a decreasing function of the total number of cluster members appeared in the population. Cluster transition is modelled with inclusion and exclusion of dynamical epistatic effects. In both cases we observe a continuous transition, driven by the mutation rate, from a dynamics with single clusters alternating in time to the coexistence of many clusters in the population. The transition between the two regimes is investigated in terms of the key parameters of the model. We find that the location and the scaling of this transition can be explained in terms of the time of first appearance of a new cluster in the population. The presence of dynamical epistatic effects results in a shift of the value of the mutation rate where the transition occurs. |
Loreto, Vittorio; Gravino, Pietro; Servedio, Vito DP; Tria, Francesca On the Emergence of Syntactic Structures: Quantifying and Modeling Duality of Patterning (Journal Article) Topics in cognitive science, 8 (2), pp. 469–480, 2016. @article{loreto2016emergence, title = {On the Emergence of Syntactic Structures: Quantifying and Modeling Duality of Patterning}, author = { Vittorio Loreto and Pietro Gravino and Vito DP Servedio and Francesca Tria}, url = {http://onlinelibrary.wiley.com/doi/10.1111/tops.12193/full}, year = {2016}, date = {2016-01-01}, journal = {Topics in cognitive science}, volume = {8}, number = {2}, pages = {469--480}, publisher = {Wiley Online Library}, abstract = {The complex organization of syntax in hierarchical structures is one of the core design features of human language. Duality of patterning refers for instance to the organization of the meaningful elements in a language at two distinct levels: a combinatorial level where meaningless forms are combined into meaningful forms and a compositional level where meaningful forms are composed into larger lexical units. The question remains wide open regarding how such a structure could have emerged. Furthermore a clear mathematical framework to quantify this phenomenon is still lacking. The aim of this paper is that of addressing these two aspects in a self-consistent way. First, we introduce suitable measures to quantify the level of combinatoriality and compositionality in a language, and present a framework to estimate these observables in human natural languages. Second, we show that the theoretical predictions of a multi-agents modeling scheme, namely the Blending Game, are in surprisingly good agreement with empirical data. In the Blending Game a population of individuals plays language games aiming at success in communication. It is remarkable that the two sides of duality of patterning emerge simultaneously as a consequence of a pure cultural dynamics in a simulated environment that contains meaningful relations, provided a simple constraint on message transmission fidelity is also considered.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The complex organization of syntax in hierarchical structures is one of the core design features of human language. Duality of patterning refers for instance to the organization of the meaningful elements in a language at two distinct levels: a combinatorial level where meaningless forms are combined into meaningful forms and a compositional level where meaningful forms are composed into larger lexical units. The question remains wide open regarding how such a structure could have emerged. Furthermore a clear mathematical framework to quantify this phenomenon is still lacking. The aim of this paper is that of addressing these two aspects in a self-consistent way. First, we introduce suitable measures to quantify the level of combinatoriality and compositionality in a language, and present a framework to estimate these observables in human natural languages. Second, we show that the theoretical predictions of a multi-agents modeling scheme, namely the Blending Game, are in surprisingly good agreement with empirical data. In the Blending Game a population of individuals plays language games aiming at success in communication. It is remarkable that the two sides of duality of patterning emerge simultaneously as a consequence of a pure cultural dynamics in a simulated environment that contains meaningful relations, provided a simple constraint on message transmission fidelity is also considered. |
2015 |
Mastroianni, Pierpaolo; Monechi, Bernardo; Liberto, Carlo; Valenti, Gaetano; Servedio, Vito DP; Loreto, Vittorio Local Optimization Strategies in Urban Vehicular Mobility (Journal Article) PloS one, 10 (12), pp. e0143799, 2015. @article{Mastroianni2015, title = {Local Optimization Strategies in Urban Vehicular Mobility}, author = {Pierpaolo Mastroianni and Bernardo Monechi and Carlo Liberto and Gaetano Valenti and Vito DP Servedio and Vittorio Loreto}, url = {http://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0143799}, doi = {doi:10.1371/journal.pone.0143799}, year = {2015}, date = {2015-12-15}, journal = {PloS one}, volume = {10}, number = {12}, pages = {e0143799}, publisher = {Public Library of Science}, abstract = {The comprehension of vehicular traffic in urban environments is crucial to achieve a good management of the complex processes arising from people collective motion. Even allowing for the great complexity of human beings, human behavior turns out to be subject to strong constraints—physical, environmental, social, economic—that induce the emergence of common patterns. The observation and understanding of those patterns is key to setup effective strategies to optimize the quality of life in cities while not frustrating the natural need for mobility. In this paper we focus on vehicular mobility with the aim to reveal the underlying patterns and uncover the human strategies determining them. To this end we analyze a large dataset of GPS vehicles tracks collected in the Rome (Italy) district during a month. We demonstrate the existence of a local optimization of travel times that vehicle drivers perform while choosing their journey. This finding is mirrored by two additional important facts, i.e., the observation that the average vehicle velocity increases by increasing the travel length and the emergence of a universal scaling law for the distribution of travel times at fixed traveled length. A simple modeling scheme confirms this scenario opening the way to further predictions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The comprehension of vehicular traffic in urban environments is crucial to achieve a good management of the complex processes arising from people collective motion. Even allowing for the great complexity of human beings, human behavior turns out to be subject to strong constraints—physical, environmental, social, economic—that induce the emergence of common patterns. The observation and understanding of those patterns is key to setup effective strategies to optimize the quality of life in cities while not frustrating the natural need for mobility. In this paper we focus on vehicular mobility with the aim to reveal the underlying patterns and uncover the human strategies determining them. To this end we analyze a large dataset of GPS vehicles tracks collected in the Rome (Italy) district during a month. We demonstrate the existence of a local optimization of travel times that vehicle drivers perform while choosing their journey. This finding is mirrored by two additional important facts, i.e., the observation that the average vehicle velocity increases by increasing the travel length and the emergence of a universal scaling law for the distribution of travel times at fixed traveled length. A simple modeling scheme confirms this scenario opening the way to further predictions. |
Rodi, Giovanna Chiara; Loreto, Vittorio; Servedio, Vito DP; Tria, Francesca Optimal Learning Paths in Information Networks (Journal Article) Scientific Reports, 5 (10286), 2015. @article{Rodi2015, title = {Optimal Learning Paths in Information Networks}, author = {Giovanna Chiara Rodi and Vittorio Loreto and Vito DP Servedio and Francesca Tria}, url = {http://www.nature.com/srep/2015/150601/srep10286/full/srep10286.html}, doi = {10.1038/srep10286}, year = {2015}, date = {2015-06-01}, journal = {Scientific Reports}, volume = {5}, number = {10286}, abstract = {Each sphere of knowledge and information could be depicted as a complex mesh of correlated items. By properly exploiting these connections, innovative and more efficient navigation strategies could be defined, possibly leading to a faster learning process and an enduring retention of information. In this work we investigate how the topological structure embedding the items to be learned can affect the efficiency of the learning dynamics. To this end we introduce a general class of algorithms that simulate the exploration of knowledge/information networks standing on well-established findings on educational scheduling, namely the spacing and lag effects. While constructing their learning schedules, individuals move along connections, periodically revisiting some concepts, and sometimes jumping on very distant ones. In order to investigate the effect of networked information structures on the proposed learning dynamics we focused both on synthetic and real-world graphs such as subsections of Wikipedia and word-association graphs. We highlight the existence of optimal topological structures for the simulated learning dynamics whose efficiency is affected by the balance between hubs and the least connected items. Interestingly, the real-world graphs we considered lead naturally to almost optimal learning performances.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Each sphere of knowledge and information could be depicted as a complex mesh of correlated items. By properly exploiting these connections, innovative and more efficient navigation strategies could be defined, possibly leading to a faster learning process and an enduring retention of information. In this work we investigate how the topological structure embedding the items to be learned can affect the efficiency of the learning dynamics. To this end we introduce a general class of algorithms that simulate the exploration of knowledge/information networks standing on well-established findings on educational scheduling, namely the spacing and lag effects. While constructing their learning schedules, individuals move along connections, periodically revisiting some concepts, and sometimes jumping on very distant ones. In order to investigate the effect of networked information structures on the proposed learning dynamics we focused both on synthetic and real-world graphs such as subsections of Wikipedia and word-association graphs. We highlight the existence of optimal topological structures for the simulated learning dynamics whose efficiency is affected by the balance between hubs and the least connected items. Interestingly, the real-world graphs we considered lead naturally to almost optimal learning performances. |
Tria, Francesca; Servedio, Vito; Mufwene, Salikoko; Loreto, Vittorio Modeling the Emergence of Contact Languages (Journal Article) PLoS ONE, 10 (4), pp. e0120771, 2015. @article{10.1371/journal.pone.0120771, title = {Modeling the Emergence of Contact Languages}, author = {Francesca Tria and Vito D.P. Servedio and Salikoko Mufwene and Vittorio Loreto}, url = {http://dx.doi.org/10.1371%2Fjournal.pone.0120771}, doi = {10.1371/journal.pone.0120771}, year = {2015}, date = {2015-01-01}, journal = {PLoS ONE}, volume = {10}, number = {4}, pages = {e0120771}, publisher = {Public Library of Science}, abstract = { Contact languages are born out of the non-trivial interaction of two (or more) parent languages. Nowadays, the enhanced possibility of mobility and communication allows for a strong mixing of languages and cultures, thus raising the issue of whether there are any pure languages or cultures that are unaffected by contact with others. As with bacteria or viruses in biological evolution, the evolution of languages is marked by horizontal transmission; but to date no reliable quantitative tools to investigate these phenomena have been available. An interesting and well documented example of contact language is the emergence of creole languages, which originated in the contacts of European colonists and slaves during the 17th and 18th centuries in exogenous plantation colonies of especially the Atlantic and Indian Ocean. Here, we focus on the emergence of creole languages to demonstrate a dynamical process that mimics the process of creole formation in American and Caribbean plantation ecologies. Inspired by the Naming Game (NG), our modeling scheme incorporates demographic information about the colonial population in the framework of a non-trivial interaction network including three populations: Europeans, Mulattos/Creoles, and Bozal slaves. We show how this sole information makes it possible to discriminate territories that produced modern creoles from those that did not, with a surprising accuracy. The generality of our approach provides valuable insights for further studies on the emergence of languages in contact ecologies as well as to test specific hypotheses about the peopling and the population structures of the relevant territories. We submit that these tools could be relevant to addressing problems related to contact phenomena in many cultural domains: e.g., emergence of dialects, language competition and hybridization, globalization phenomena. },keywords = {}, pubstate = {published}, tppubtype = {article} } <p>Contact languages are born out of the non-trivial interaction of two (or more) parent languages. Nowadays, the enhanced possibility of mobility and communication allows for a strong mixing of languages and cultures, thus raising the issue of whether there are any pure languages or cultures that are unaffected by contact with others. As with bacteria or viruses in biological evolution, the evolution of languages is marked by horizontal transmission; but to date no reliable quantitative tools to investigate these phenomena have been available. An interesting and well documented example of contact language is the emergence of creole languages, which originated in the contacts of European colonists and slaves during the 17th and 18th centuries in exogenous plantation colonies of especially the Atlantic and Indian Ocean. Here, we focus on the emergence of creole languages to demonstrate a dynamical process that mimics the process of creole formation in American and Caribbean plantation ecologies. Inspired by the Naming Game (NG), our modeling scheme incorporates demographic information about the colonial population in the framework of a non-trivial interaction network including three populations: Europeans, Mulattos/Creoles, and Bozal slaves. We show how this sole information makes it possible to discriminate territories that produced modern creoles from those that did not, with a surprising accuracy. The generality of our approach provides valuable insights for further studies on the emergence of languages in contact ecologies as well as to test specific hypotheses about the peopling and the population structures of the relevant territories. We submit that these tools could be relevant to addressing problems related to contact phenomena in many cultural domains: e.g., emergence of dialects, language competition and hybridization, globalization phenomena.</p> |
Cuskley, Christine; Colaiori, Francesca; Castellano, Claudio; Loreto, Vittorio; Pugliese, Martina; Tria, Francesca The adoption of linguistic rules in native and non-native speakers: Evidence from a Wug task (Journal Article) Journal of Memory and Language, 84 , pp. 205 - 223, 2015, ISSN: 0749-596X. @article{Cuskley2015205, title = {The adoption of linguistic rules in native and non-native speakers: Evidence from a Wug task}, author = {Christine Cuskley and Francesca Colaiori and Claudio Castellano and Vittorio Loreto and Martina Pugliese and Francesca Tria}, url = {http://www.sciencedirect.com/science/article/pii/S0749596X15000790}, doi = {http://dx.doi.org/10.1016/j.jml.2015.06.005}, issn = {0749-596X}, year = {2015}, date = {2015-01-01}, journal = {Journal of Memory and Language}, volume = {84}, pages = {205 - 223}, abstract = {Several recent theories have suggested that an increase in the number of non-native speakers in a language can lead to changes in morphological rules. We examine this experimentally by contrasting the performance of native and non-native English speakers in a simple Wug-task, showing that non-native speakers are significantly more likely to provide non -ed (i.e., irregular) past-tense forms for novel verbs than native speakers. Both groups are sensitive to sound similarities between new words and existing words (i.e., are more likely to provide irregular forms for novel words which sound similar to existing irregulars). Among both natives and non-natives, irregularizations are non-random; that is, rather than presenting as truly irregular inflectional strategies, they follow identifiable sub-rules present in the highly frequent set of irregular English verbs. Our results shed new light on how native and non-native learners can affect language structure.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Several recent theories have suggested that an increase in the number of non-native speakers in a language can lead to changes in morphological rules. We examine this experimentally by contrasting the performance of native and non-native English speakers in a simple Wug-task, showing that non-native speakers are significantly more likely to provide non -ed (i.e., irregular) past-tense forms for novel verbs than native speakers. Both groups are sensitive to sound similarities between new words and existing words (i.e., are more likely to provide irregular forms for novel words which sound similar to existing irregulars). Among both natives and non-natives, irregularizations are non-random; that is, rather than presenting as truly irregular inflectional strategies, they follow identifiable sub-rules present in the highly frequent set of irregular English verbs. Our results shed new light on how native and non-native learners can affect language structure. |
Colaiori, Francesca; Castellano, Claudio; Cuskley, Christine; Loreto, Vittorio; Pugliese, Martina; Tria, Francesca General three-state model with biased population replacement: Analytical solution and application to language dynamics (Journal Article) Phys. Rev. E, 91 , pp. 012808, 2015. @article{PhysRevE.91.012808b, title = {General three-state model with biased population replacement: Analytical solution and application to language dynamics}, author = { Francesca Colaiori and Claudio Castellano and Christine F. Cuskley and Vittorio Loreto and Martina Pugliese and Francesca Tria}, url = {http://link.aps.org/doi/10.1103/PhysRevE.91.012808}, doi = {10.1103/PhysRevE.91.012808}, year = {2015}, date = {2015-01-01}, journal = {Phys. Rev. E}, volume = {91}, pages = {012808}, publisher = {American Physical Society}, abstract = {Empirical evidence shows that the rate of irregular usage of English verbs exhibits discontinuity as a function of their frequency: the most frequent verbs tend to be totally irregular. We aim to qualitatively understand the origin of this feature by studying simple agent-based models of language dynamics, where each agent adopts an inflectional state for a verb and may change it upon interaction with other agents. At the same time, agents are replaced at some rate by new agents adopting the regular form. In models with only two inflectional states (regular and irregular), we observe that either all verbs regularise irrespective of their frequency, or a continuous transition occurs between a low-frequency state, where the lemma becomes fully regular, and a high-frequency one, where both forms coexist. Introducing a third (mixed) state, wherein agents may use either form, we find that a third, qualitatively different behaviour may emerge, namely, a discontinuous transition in frequency. We introduce and solve analytically a very general class of three-state models that allows us to fully understand these behaviours in a unified framework. Realistic sets of interaction rules, including the well-known naming game (NG) model, result in a discontinuous transition, in agreement with recent empirical findings. We also point out that the distinction between speaker and hearer in the interaction has no effect on the collective behaviour. The results for the general three-state model, although discussed in terms of language dynamics, are widely applicable.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Empirical evidence shows that the rate of irregular usage of English verbs exhibits discontinuity as a function of their frequency: the most frequent verbs tend to be totally irregular. We aim to qualitatively understand the origin of this feature by studying simple agent-based models of language dynamics, where each agent adopts an inflectional state for a verb and may change it upon interaction with other agents. At the same time, agents are replaced at some rate by new agents adopting the regular form. In models with only two inflectional states (regular and irregular), we observe that either all verbs regularise irrespective of their frequency, or a continuous transition occurs between a low-frequency state, where the lemma becomes fully regular, and a high-frequency one, where both forms coexist. Introducing a third (mixed) state, wherein agents may use either form, we find that a third, qualitatively different behaviour may emerge, namely, a discontinuous transition in frequency. We introduce and solve analytically a very general class of three-state models that allows us to fully understand these behaviours in a unified framework. Realistic sets of interaction rules, including the well-known naming game (NG) model, result in a discontinuous transition, in agreement with recent empirical findings. We also point out that the distinction between speaker and hearer in the interaction has no effect on the collective behaviour. The results for the general three-state model, although discussed in terms of language dynamics, are widely applicable. |
Baronchelli, Andrea; Loreto, Vittorio; Puglisi, Andrea Individual biases, cultural evolution, and the statistical nature of language universals: The case of colour naming systems (Journal Article) PloS one, 10 (5), pp. e0125019, 2015. @article{baronchelli2015individual, title = {Individual biases, cultural evolution, and the statistical nature of language universals: The case of colour naming systems}, author = {Andrea Baronchelli and Vittorio Loreto and Andrea Puglisi}, url = {http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0125019}, year = {2015}, date = {2015-01-01}, journal = {PloS one}, volume = {10}, number = {5}, pages = {e0125019}, publisher = {Public Library of Science}, abstract = {Language universals have long been attributed to an innate Universal Grammar. An alternative explanation states that linguistic universals emerged independently in every language in response to shared cognitive or perceptual biases. A computational model has recently shown how this could be the case, focusing on the paradigmatic example of the universal properties of colour naming patterns, and producing results in quantitative agreement with the experimental data. Here we investigate the role of an individual perceptual bias in the framework of the model. We study how, and to what extent, the structure of the bias influences the corresponding linguistic universal patterns. We show that the cultural history of a group of speakers introduces population-specific constraints that act against the pressure for uniformity arising from the individual bias, and we clarify the interplay between these two forces.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Language universals have long been attributed to an innate Universal Grammar. An alternative explanation states that linguistic universals emerged independently in every language in response to shared cognitive or perceptual biases. A computational model has recently shown how this could be the case, focusing on the paradigmatic example of the universal properties of colour naming patterns, and producing results in quantitative agreement with the experimental data. Here we investigate the role of an individual perceptual bias in the framework of the model. We study how, and to what extent, the structure of the bias influences the corresponding linguistic universal patterns. We show that the cultural history of a group of speakers introduces population-specific constraints that act against the pressure for uniformity arising from the individual bias, and we clarify the interplay between these two forces. |
Sakellariou, Jason; and Tria, Francesca; Vittorio, Loreto; Pachet, François Maximum entropy model for melodic patterns (Inproceeding) ICML Workshop on Constructive Machine Learning, 2015. @inproceedings{sakellariou2015maximum, title = {Maximum entropy model for melodic patterns}, author = {Jason Sakellariou and and Francesca Tria and Loreto Vittorio and François Pachet}, url = {https://arxiv.org/abs/1610.03414}, year = {2015}, date = {2015-01-01}, booktitle = {ICML Workshop on Constructive Machine Learning}, abstract = {We introduce a model for music generation where melodies are seen as a network of interacting notes. Starting from the principle of maximum entropy we assign to this network a probability distribution, which is learned from an existing musical corpus. We use this model to generate novel musical sequences that mimic the style of the corpus. Our main result is that this model can reproduce high-order patterns despite having a polynomial sample complexity. This is in contrast with the more traditionally used Markov models that have an exponential sample complexity.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } We introduce a model for music generation where melodies are seen as a network of interacting notes. Starting from the principle of maximum entropy we assign to this network a probability distribution, which is learned from an existing musical corpus. We use this model to generate novel musical sequences that mimic the style of the corpus. Our main result is that this model can reproduce high-order patterns despite having a polynomial sample complexity. This is in contrast with the more traditionally used Markov models that have an exponential sample complexity. |
2014 |
Tria, Francesca; Loreto, Vittorio; Servedio, Vito Domenico Pietro; Strogatz, Steven The dynamics of correlated novelties (Journal Article) Nature Scientific Reports, 4 (5890), 2014. @article{b, title = {The dynamics of correlated novelties}, author = {Francesca Tria and Vittorio Loreto and Vito Domenico Pietro Servedio and Steven H. Strogatz}, url = {http://www.nature.com/srep/2014/140731/srep05890/full/srep05890.html}, year = {2014}, date = {2014-01-01}, journal = {Nature Scientific Reports}, volume = {4}, number = {5890}, publisher = {Nature Publishing Group}, abstract = {Novelties are a familiar part of daily life. They are also fundamental to the evolution of biological systems, human society, and technology. By opening new possibilities, one novelty can pave the way for others in a process that Kauffman has called expanding the adjacent possible . The dynamics of correlated novelties, however, have yet to be quantified empirically or modeled mathematically. Here we propose a simple mathematical model that mimics the process of exploring a physical, biological, or conceptual space that enlarges whenever a novelty occurs. The model, a generalization of Polya\'s urn, predicts statistical laws for the rate at which novelties happen (Heaps\' law) and for the probability distribution on the space explored (Zipf\'s law), as well as signatures of the process by which one novelty sets the stage for another. We test these predictions on four data sets of human activity: the edit events of Wikipedia pages, the emergence of tags in annotation systems, the sequence of words in texts, and listening to new songs in online music catalogues. By quantifying the dynamics of correlated novelties, our results provide a starting point for a deeper understanding of the adjacent possible and its role in biological, cultural, and technological evolution.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Novelties are a familiar part of daily life. They are also fundamental to the evolution of biological systems, human society, and technology. By opening new possibilities, one novelty can pave the way for others in a process that Kauffman has called expanding the adjacent possible . The dynamics of correlated novelties, however, have yet to be quantified empirically or modeled mathematically. Here we propose a simple mathematical model that mimics the process of exploring a physical, biological, or conceptual space that enlarges whenever a novelty occurs. The model, a generalization of Polya's urn, predicts statistical laws for the rate at which novelties happen (Heaps' law) and for the probability distribution on the space explored (Zipf's law), as well as signatures of the process by which one novelty sets the stage for another. We test these predictions on four data sets of human activity: the edit events of Wikipedia pages, the emergence of tags in annotation systems, the sequence of words in texts, and listening to new songs in online music catalogues. By quantifying the dynamics of correlated novelties, our results provide a starting point for a deeper understanding of the adjacent possible and its role in biological, cultural, and technological evolution. |
2013 |
Caminiti, Saverio; Cicali, Claudio; Gravino, Pietro; Loreto, Vittorio; Servedio, Vito DP; Sirbu, Alina; Tria, Francesca XTribe: a web-based social computation platform (Inproceeding) Cloud and Green Computing (CGC), 2013 Third International Conference on, pp. 397–403, IEEE 2013. @inproceedings{caminiti2013xtribe, title = {XTribe: a web-based social computation platform}, author = {Caminiti, Saverio and Cicali, Claudio and Gravino, Pietro and Loreto, Vittorio and Servedio, Vito DP and Sirbu, Alina and Tria, Francesca}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6686061 http://arxiv.org/pdf/1401.4578v1.pdf}, year = {2013}, date = {2013-01-01}, booktitle = {Cloud and Green Computing (CGC), 2013 Third International Conference on}, pages = {397--403}, organization = {IEEE}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |