Rishiraj Saha Roy will present his work on November 26th at 2pm. It will be online on Zoom at https://us05web.zoom.us/j/84967892694?pwd=cGthbHM0b2phdkJ3VFZBSEFOOUhIZz09.

Title: Graph Methods for Complex and Conversational Question Answering over Knowledge Bases

Abstract: Answering complex and conversational questions over curated and open knowledge bases represent areas of intense focus in the IR and NLP communities today. While complex questions require joint disambiguation of multiple entities and predicates, the conversational setup needs resolution of implicit context in a multi-turn setting. Recently, search based on graph models has shown great promise in dealing with these particularly challenging settings in QA, in comparison to more traditional querying with structured logical forms. The talk will roughly have two parts, corresponding to recent approaches from our group for the two settings. For complex question answering, we propose a robust technique based on Group Steiner Trees that can operate on noisy graphs constructed on-the-fly from textual evidence on the Web. In the second part of the talk, we discuss how iterative graph traversal in an unsupervised setup can be used for developing a reusable module that can enable standalone QA systems handle conversational questions. We will conclude with some key insights and interesting open directions in question answering.

Bio: Rishiraj Saha Roy is a Senior Researcher at the Max Planck Institute for Informatics (MPII), Saarbruecken, Germany. He leads the research group on Question Answering, that focuses on robust and interpretable solutions for answering natural language questions over structured and unstructured data. He has about five years of research experience on question answering. In recent years, he has served on the PCs of conferences like SIGIR, CIKM, AAAI, EMNLP, and NAACL, and published at venues like SIGIR, CIKM, WSDM, WWW, and NAACL. Prior to joining MPII, he worked for one and a half years as a Computer Scientist at Adobe Research. He completed his PhD as a Microsoft Research India Fellow from the Indian Institute of Technology (IIT) Kharagpur. More information about his research can be found at http://people.mpi-inf.mpg.de/~rsaharo/.