Search and Data Mining research at Yahoo Research involves regular Web search (including content acquisition, content understanding, query analysis, and content ranking) as well as mobile and mail search. As part of content acquisition, our research focuses on efficient means for crawling the Web, ensuring freshness, and performing topic-focused crawls or deep crawls. Content understanding focuses on document structural analysis, information extraction, categorization and clustering, etc. Query analysis and content ranking focus on how to predict user intent and how to match and rank the most relevant information satisfying user needs.