Adwait Ratnaparkhi is a Senior Director in the Advertising Sciences Dept. of Yahoo. Prior to joining Yahoo, Adwait held a variety of research and development positions in the areas of online advertising, machine learning, natural language processing, and conversational systems. He received a B.S.E. from Princeton University in 1992 and a Ph.D. from the University of Pennsylvania in 1998, both in Computer Science. His Ph.D. thesis was titled "Maximum entropy models for natural language ambiguity resolution". His past employers include the research laboratories of Nuance, IBM, and Microsoft. He has also worked for several startups, including 33Across, where he served as the Chief Scientist.