#Social Networks #Recommendation algorithms #Stochastic Blocks

Predicting Human Preferences Using the Block Structure of Complex Social Networks

Authors: Roger Guimerà, Alejandro Llorente, Esteban Moro y Marta Sales-Pardo Journal: PLoS ONE 7, e44620 (2012) LINK Abstract: With ever-increasing available data, predicting individuals' preferences and helping them locate the most relevant information has become a pressing need. Understanding and predicting preferences is also important from a fundamental point of view, as part of what has been called a “new” computational social science. Here, we propose a novel approach based on stochastic block models, which have been developed by sociologists as plausible models of complex networks of social interactions. ...

It was a delicious assignment, infinitely complicated

I have just read an amazing book “Shibumi” by Trevanian (a.k.a. Rodney William Whitaker) probably the best spy novel I have read so far. In the book, a big data computer (called Fat Boy) is operated by a “data scientist” (although is not called that way). I enjoyed very much the following paragraph, an analogy of the emptiness of big data without insight and also a musing about how difficult is to find relationships from activity data (the kind of research we do! ...

Which chart to use

In most of my talks I present quantitative evidence of patterns, data exploration or results. But which is the right way to show that evidence? Worry no more: the Extreme Presentation Method helps you to decide with this chart chooser (click here to download the pdf) My impression is that this chart chooser is good for small data. For big data some of the charts render useless. For example, read the insightfull post Don’t use Scatterplots by Chris Stucchio on why is not a good idea to use scatterplots to show relationship between bivariate data when you have large amounts of data. ...

#Agents #Complexity #Finance #Stock Market #Market Impact

Agent-specific impact of single trades in financial markets

Authors: Alex Bladon, Esteban Moro y Tobias Galla Journal: Physical Review E 85, 036103 (2012) LINK | arXiv Abstract: We present an analysis of the price impact associated with single trades effected by different financial firms. Using data from the Spanish Stock Market, we find a high degree of heterogeneity across different market members, both in the instantaneous impact functions and in the time-dependent market response to trades by individual members. ...

#Marketing #Viral #Social Networks

Branching dynamics of viral information spreading

Authors: José Luis Iribarren and Esteban Moro Journal: Physical Review E 84, 046116 (2011) LINK | arXiv Abstract: Despite its importance for rumors or innovations propagation, peer-to-peer collaboration, social networking, or marketing, the dynamics of information spreading is not well understood. Since the diffusion depends on the heterogeneous patterns of human behavior and is driven by the participants’ decisions, its propagation dynamics shows surprising properties not explained by traditional epidemic or contagion models. ...

#Social Networks #Twitter #Weak Ties

Social Features of Online Networks: The Strength of Intermediary Ties in Online Social Media

Authors: P. A. Grabowicz, J. J. Ramasco, E. Moro, J. P. Pujol and V. M. Eguiluz Journal: PLoS ONE 7(1): e29358 (2012). LINK Abstract: An increasing fraction of today’s social interactions occur using online social media as communication channels. Recent worldwide events, such as social movements in Spain or revolts in the Middle East, highlight their capacity to boost people’s coordination. Online networks display in general a rich internal structure where users can choose among different types and intensity of interactions. ...