Yifan Gao

Yifan is an Applied Scientist II at Amazon Search/A9. He obtained his Ph.D. in Computer Science at the Chinese University of Hong Kong. Prior to that, Yifan received his B.Eng. from Beihang University, China. He interned at Amazon Search (A9.com), AWS AI Labs, Salesforce Research, and Tencent AI Lab during his Ph.D. study.

Research Internship positions in Amazon Search/A9 are available. Feel free to send your CV to me if you are interested.

My research interests are in natural language processing and machine learning. During my PhD study, I teach machines to ask and answer reading comprehension questions driven by two goals:

• Knowledge Assessment: Asking questions is an effective approach to assess the understanding of users towards a passage of text. I work on 1) how to ask questions with different levels of difficulty [IJCAI'19]; 2) how to ask interconnected questions in a conversation for interactiveness and persistence [ACL'19], and 3) how to generate distractors (wrong options) in multiple-choice reading comprehension questions [AAAI'19].
• Information Acquisition: Many questions are inherently underspecified or ambiguous in our day-to-day conversations. In this case, the machine needs to 1) keep asking follow-up questions in a dialog until it gathers enough information to answer those high-level questions [ACL'20] [EMNLP'20] [arXiv'21]; or 2) present a series of disambiguated QA pairs when the query is ambiguous[ACL'21].