Time+Place: Thursday 24/12/2015 14:30 Room 337-8 Taub Bld.
Title: Nothing but net? content and network factors in information diffusion
Speaker: Oren Tsur - CS-Lecture http://people.seas.harvard.edu/~orentsur
Affiliation: Harvard's School for Engineering and Applied Science (SEAS)
Host: Benny Kimelfeld


Information diffusion is the process in which nuggets of information 
spread in a network (typically a social network). This is a complex 
process that depends on the network topology, the social structures and 
the information itself (content/language). In this talk I will discuss 
information diffusion from these different yet complementary 
perspectives. In the first part  of the talk I will focus on the 
features of the diffusing information.  I will  present a gradient 
boosted trees algorithm modified for learning user preferences of 
Twitter hashtags. In the second part of my talk I will focus on the 
network structure. I will use exponential random graph models (ERGM) in 
order to learn what latent factors contribute to network formation and I 
will show how network structure and social roles contribute to the 
information spread. Specifically, I will present promising results 
obtained on political networks in the American political system and 
analysis of the partisan use of political hashtags.

In both parts I put emphasis on interpretable models that go beyond 
accurate prediction and  facilitate a better understanding of complex 
social processes. 

Short Bio:

Oren is a postdoctoral fellow at the Harvard's School for Engineering 
and Applied Science (SEAS) jointly with the Network Science Institute at 
Northeastern University and is also affiliated with Harvard's Institute 
for Quantitative Social Science (IQSS). He received  his Ph.D. in 
Computer Science from the Hebrew University at 2013. In his work he 
combines natural language processing and network analysis in order to 
model and predict complex social dynamics. His work was published in 
both the NLP and the web/data science communities. Oren co-organized the 
workshop on NLP and Social Dynamics at ACL 2014, is co-organizing the 
EMNLP 2016 workshop on NLP and Computational Social Science  and will be 
giving the tutorial on Understanding Offline Political Systems by Mining 
Online Political Data at WSDM 2016. His research on sarcasm detection 
(with Dmitry Davidov and Ari Rappoport) was listed in Time Magazine 
special issue as one of the 50 best inventions of the year (2010).