Learning Deep Structured Semantic Models for Web Search using Clickthrough Data Po-Sen Huang University of Illinois at Urbana-Champaign 405 N Mathews Ave. Urbana, IL 61801 USA huang146@illinois.edu Xiaodong He, Jianfeng Gao, Li Deng, Alex Acero, Larry Heck Microsoft Research, Redmond, WA 98052 USA {xiaohe, jfgao, deng, alexac, lheck}@microsoft.com ABSTRACT Latent semantic models, such as LSA, int