Under the Hood: The natural language interface of Graph Search

This post details the technical architecture and implementation of the natural language interface for Facebook's Graph Search. It covers the challenges of keyword-based search, the convergence on a natural language interface, and the core components: entity recognition and resolution, lexical analysis, and semantic parsing. It also elaborates on the use of a weighted context-free grammar (WCFG) with semantic functions and a cost structure for ranking parse trees, as well as the linguistic resources and language models used for entity detection and lexical analysis to handle varied user inputs.