Introduction to Computer Vision Introducti on Part I Feature Extraction (1) Zhigang Zhu, City College of New York [email protected] CSc I6716 Fall 2009 Image Enhancement
Jan 21, 2016
KDD 2011 Doctoral Session
Modeling Trustworthiness of Online ContentV. G. Vinod Vydiswaran
Advisors: Prof.ChengXiang Zhai, Prof.Dan RothUniversity of Illinois at Urbana-Champaign
Incorporating text in trust models
Three directions of research
Credibility assessment woes
Acknowledgments
My research is supported partially by the Multimodal Information Access and Synthesis (MIAS) Center at the University of Illinois at Urbana-Champaign, part of CCICADA, a DHS Science and Technology Center of Excellence, and grants from the Army Research Laboratory.
Contact details
[email protected], [email protected], [email protected]
Claim 1
Claim n
Claim 2
.
.
.
Evidence ClaimsSources
Web sources
Evidence passages
Claim sentences
Incorporates semantics in trust computation using evidence.
Claims need not be structured tuples – they can be free-text sentences.
Framework does not assume that accurate Information Extraction is available.
A source can have different trust profile for different claims – not all claims from a source get equal weight.
Advantages over traditional models
Traditional two-layer fact-finder models
Claim 1
Claim n
Claim 2
…
[Yin, et al., 2007; Pasternack & Roth, 2010]
Need to determine the truth value of a claim.
Many information types available to gauge trustworthiness
Source credibility and the power of information network Evidence trustworthiness Signals from community knowledge Contrastive viewpoints for claims Biases of users accessing the information
The goal is to recognize credible information by combining these features
Next step is to understand how human biases interact with credibility of information they access
Conclusion and future research steps
Community knowledge to validate claims
Veracity ofnews reporting
Trustworthiness of news stories
Credibility of news sources
Building trust models over pieces of evidence
Content-driven trust propagation framework (KDD 2011)
Utilizes similarity and trustworthiness of evidence to measure trustworthiness of sources and claims.
Scoring claims based on community knowledge
Find treatment relations in health message boards and forums
Verify if the perception formed from reading forums correlates with validity of treatments (as approved by FDA)
Squashing rumors with evidence search
Find evidence for claims from a large text collection (ACL 2009)
Find contrasting evidence (ongoing)
Even reputed sources make mistakes Some claims (and sources) are
purposefully misleading Not all claims made by a source is
equally trustworthy Often, contradictory claims are both
supported by credible evidence How to verify free-text claims?
Claim DB
Claim DB
Claim DB
Claim DB
Evidence & Support DB
Match up claims to evidence
Rate sites based on matching claims and
their support
Extract relevant claims and evidence
1 2 3
Contrastive evidence retrieval
Lookup pieces of evidence
supporting and opposing the claim
Lookup pieces of evidence only on
relevance
Traditional search
Evidence search
Scalable Entailed Relation Recognizer
Expanded Lexical
Retrieval
Entailment Recognition
Text Corpus
Indexes
Hypothesis(Claim) Relation
[Initial work at ACL 2009]
1
2 3
[KDD-DMH 2011]
[KDD 2011]