SUNMONTUEWEDTHUFRISAT
Events for July 15, 2016
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AI SEMINAR
Fri, Jul 15, 2016 @ 11:00 AM - 12:00 PM
Information Sciences Institute
Conferences, Lectures, & Seminars
Speaker: Keith Burghardt,
Talk Title: Understanding the Dynamics of Collective Decisions
Series: AI Seminar
Abstract: In a microscopic setting, humans behave in rich and unexpected ways. In a macroscopic setting, however, distinctive patterns of group behavior emerge, leading researchers to search for an underlying mechanism. The aim of this talk is to analyze the macroscopic patterns of collective decisions in order to discern how group opinions form at the microscopic level. To do so, we first explore the mechanisms that underlie competing ideas using agent-based models (ABMs). We find that simple rules can accurately reconstruct the macroscopic patterns we see in data as diverse as elections and juries. Next, we model collective decision-making in online question and answer boards, and find that a simple individual-level model can capture important features of user behavior, and heuristics appears to predict dynamics with increasing accuracy as the number of answers grow, suggesting information overload undermines collective decisions. Overall, these models reveal two important findings. First, our work begins to untangle how human psychology affects macroscopic behavior: stubbornness, in which users increasingly stick to their latest opinion, is a necessary component in our ABMs to produce the macroscopic patterns we see in many diverse datasets. Furthermore, our models suggest limitations of the wisdom of crowds, in which groups produce better decisions than individuals, in common systems may be undermined by influence and information overload.
Biography: Keith Burghardt is a summer research assistant at ISI under Kristina Lerman studying the collective decisions among users of question and answer boards. He holds a Bachelors of Science in Physics at the University of Maryland, and was recently awarded a Doctorate in Philosophy in Physics from the same university under Michelle Girvan and William Rand. His research has focused on applying statistical mechanics, and other physics-based approaches toward understanding collective social phenomena, including work as diverse as jury decisions, epidemics, and online environments.
No Webcast available
Host: Kristina Lerman
Location: Information Science Institute (ISI) - 6th fl Large CR (Room 689)
Audiences: Everyone Is Invited
Contact: Alma Nava / Information Sciences Institute
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NL Seminar-Commonsense Knowledge Base Completion
Fri, Jul 15, 2016 @ 03:00 PM - 04:00 PM
Information Sciences Institute
Conferences, Lectures, & Seminars
Speaker: Xiang Li, University of Massachusetts Amherst
Talk Title: Commonsense Knowledge Base Completion
Series: Natural Language Seminar
Abstract: We enrich a curated resource of commonsense knowledge by formulating the problem as one of knowledge base completion KBC. Most work in KBC focuses on knowledge bases like Freebase that relate entities drawn from a fixed set. However, the tuples in Concept Net Speer and Havasi define relations between an unbounded set of phrases. We develop neural network models for scoring tuples on arbitrary phrases and evaluate them by their ability to distinguish true held out tuples from false ones. We find strong performance from a bilinear model using a simple additive architecture to model phrases. We manually evaluate our trained models ability to assign quality scores to novel tuples finding that it can propose tuples at the same quality level as medium confidence tuples from Concept Net.
Biography: Xiang Li is asummer intern under the supervision of Prof Kevin Knight and Prof Daniel Marcu. She is also going to be a PhD student at the University of Massachusetts Amherst in Andrew McCallums research group in this coming Fall. She got her BS at the East China Normal University Shanghai China and got her M.S at the University of Chicago. Her research interest mainly focused on natural language processing and machine learning. This work is done when she was in Chicago working with Prof Kevin Gimpel at TTIC Toyota Technological Institute at Chicago.
Host: Xing Shi and Kevin Knight
More Info: http://nlg.isi.edu/nl-seminar/
Location: Information Science Institute (ISI) - 6th Floor -CR # 689; ISI-Marina del Rey
Audiences: Everyone Is Invited
Contact: Peter Zamar
Event Link: http://nlg.isi.edu/nl-seminar/
