211 research outputs found
VIP: Incorporating Human Cognitive Biases in a Probabilistic Model of Retweeting
Information spread in social media depends on a number of factors, including
how the site displays information, how users navigate it to find items of
interest, users' tastes, and the `virality' of information, i.e., its
propensity to be adopted, or retweeted, upon exposure. Probabilistic models can
learn users' tastes from the history of their item adoptions and recommend new
items to users. However, current models ignore cognitive biases that are known
to affect behavior. Specifically, people pay more attention to items at the top
of a list than those in lower positions. As a consequence, items near the top
of a user's social media stream have higher visibility, and are more likely to
be seen and adopted, than those appearing below. Another bias is due to the
item's fitness: some items have a high propensity to spread upon exposure
regardless of the interests of adopting users. We propose a probabilistic model
that incorporates human cognitive biases and personal relevance in the
generative model of information spread. We use the model to predict how
messages containing URLs spread on Twitter. Our work shows that models of user
behavior that account for cognitive factors can better describe and predict
user behavior in social media.Comment: SBP 201
Validation of Dunbar's number in Twitter conversations
Modern society's increasing dependency on online tools for both work and
recreation opens up unique opportunities for the study of social interactions.
A large survey of online exchanges or conversations on Twitter, collected
across six months involving 1.7 million individuals is presented here. We test
the theoretical cognitive limit on the number of stable social relationships
known as Dunbar's number. We find that users can entertain a maximum of 100-200
stable relationships in support for Dunbar's prediction. The "economy of
attention" is limited in the online world by cognitive and biological
constraints as predicted by Dunbar's theory. Inspired by this empirical
evidence we propose a simple dynamical mechanism, based on finite priority
queuing and time resources, that reproduces the observed social behavior.Comment: 8 pages, 6 figure
Circadian patterns of Wikipedia editorial activity: A demographic analysis
Wikipedia (WP) as a collaborative, dynamical system of humans is an
appropriate subject of social studies. Each single action of the members of
this society, i.e. editors, is well recorded and accessible. Using the
cumulative data of 34 Wikipedias in different languages, we try to characterize
and find the universalities and differences in temporal activity patterns of
editors. Based on this data, we estimate the geographical distribution of
editors for each WP in the globe. Furthermore we also clarify the differences
among different groups of WPs, which originate in the variance of cultural and
social features of the communities of editors
A gauge invariant chiral unitary framework for kaon photo- and electroproduction on the proton
We present a gauge invariant approach to photoproduction of mesons on
nucleons within a chiral unitary framework. The interaction kernel for
meson-baryon scattering is derived from the chiral effective Lagrangian and
iterated in a Bethe-Salpeter equation. Within the leading order approximation
to the interaction kernel, data on kaon photoproduction from SAPHIR, CLAS and
CBELSA/TAPS are analyzed in the threshold region. The importance of gauge
invariance and the precision of various approximations in the interaction
kernel utilized in earlier works are discussed.Comment: 23 pages, 13 figs, EPJ A styl
Coherent Moving States in Highway Traffic (Originally: Moving Like a Solid Block)
Recent advances in multiagent simulations have made possible the study of
realistic traffic patterns and allow to test theories based on driver
behaviour. Such simulations also display various empirical features of traffic
flows, and are used to design traffic controls that maximise the throughput of
vehicles in heavily transited highways. In addition to its intrinsic economic
value, vehicular traffic is of interest because it may throw light on some
social phenomena where diverse individuals competitively try to maximise their
own utilities under certain constraints.
In this paper, we present simulation results that point to the existence of
cooperative, coherent states arising from competitive interactions that lead to
a new phenomenon in heterogeneous highway traffic. As the density of vehicles
increases, their interactions cause a transition into a highly correlated state
in which all vehicles practically move with the same speed, analogous to the
motion of a solid block. This state is associated with a reduced lane changing
rate and a safe, high and stable flow. It disappears as the vehicle density
exceeds a critical value. The effect is observed in recent evaluations of Dutch
traffic data.Comment: Submitted on April 21, 1998. For related work see
http://www.theo2.physik.uni-stuttgart.de/helbing.html and
http://www.parc.xerox.com/dynamics
Error and attack tolerance of complex networks
Many complex systems, such as communication networks, display a surprising
degree of robustness: while key components regularly malfunction, local
failures rarely lead to the loss of the global information-carrying ability of
the network. The stability of these complex systems is often attributed to the
redundant wiring of the functional web defined by the systems' components. In
this paper we demonstrate that error tolerance is not shared by all redundant
systems, but it is displayed only by a class of inhomogeneously wired networks,
called scale-free networks. We find that scale-free networks, describing a
number of systems, such as the World Wide Web, Internet, social networks or a
cell, display an unexpected degree of robustness, the ability of their nodes to
communicate being unaffected by even unrealistically high failure rates.
However, error tolerance comes at a high price: these networks are extremely
vulnerable to attacks, i.e. to the selection and removal of a few nodes that
play the most important role in assuring the network's connectivity.Comment: 14 pages, 4 figures, Late
Evolution of Cooperation and Coordination in a Dynamically Networked Society
Situations of conflict giving rise to social dilemmas are widespread in
society and game theory is one major way in which they can be investigated.
Starting from the observation that individuals in society interact through
networks of acquaintances, we model the co-evolution of the agents' strategies
and of the social network itself using two prototypical games, the Prisoner's
Dilemma and the Stag Hunt. Allowing agents to dismiss ties and establish new
ones, we find that cooperation and coordination can be achieved through the
self-organization of the social network, a result that is non-trivial,
especially in the Prisoner's Dilemma case. The evolution and stability of
cooperation implies the condensation of agents exploiting particular game
strategies into strong and stable clusters which are more densely connected,
even in the more difficult case of the Prisoner's Dilemma.Comment: 18 pages, 14 figures. to appea
On the Refractive Index of Ageing Dispersions of Laponite
Aqueous dispersion of Laponite at low ionic concentration is of interest
since it undergoes structural evolution with respect to time, which is usually
termed as ageing. In this work we study the refractive index behavior as a
function of ageing time, concentration and temperature. We observed that the
extended Lorenz-Lorentz equation fitted the refractive index dependence on
concentration and temperature very well. The refractive index did not show any
dependence on ageing time. However, the dependence of refractive index on
concentration showed a marked change as the system underwent transition from an
isotropic to a biphasic state. The slope of the refractive index-density data
is remarkably close to that of water at all Laponite concentrations. In the
context of transport phenomena, optical measurements such as interferometry can
exploit the water-like behavior of Laponite dispersions.Comment: 13 pages, 3 figures, to appear in Applied Clay Scienc
Testing Propositions Derived from Twitter Studies: Generalization and Replication in Computational Social Science
Replication is an essential requirement for scientific discovery. The current study aims to generalize and replicate 10 propositions made in previous Twitter studies using a representative dataset. Our findings suggest 6 out of 10 propositions could not be replicated due to the variations of data collection, analytic strategies employed, and inconsistent measurements. The study’s contributions are twofold: First, it systematically summarized and assessed some important claims in the field, which can inform future studies. Second, it proposed a feasible approach to generating a random sample of Twitter users and its associated ego networks, which might serve as a solution for answering social-scientific questions at the individual level without accessing the complete data archive.published_or_final_versio
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