"Semantic Search" - understanding what it is
We all use 'search engine' like Google to get what we are looking for. We type a keyword and get pointed to resources that contain mentions of that keyword; and they are very well ordered based on multiple relevant parameters. This is a typical "statistical" search...
1. But, what if you had to search something like" Directors of Kate Winslet"? A statistical search engine does not understand the information goal; but merely returns the results which match the keywords. The top results seen on a statistical search engine page are not about 'people who have directed Kate Winslet'; but about 'Kate Winslet's director husband'.. simply because the user keywords match these texts also. The other shortcoming is that the results are essentially web-pages which need to be manually ingested to find answers to information goal. Then there is also a repetition of information across web-pages.
Let me now introduce "Semantic Search". The literal meaning of the word 'semantics' is 'meaning'. And thus, 'Semantic search' translates to 'meaning based search' ..
Semantic search aims to address these issues by applying semantics or meaning in 2 places - by understanding the meaning of keyword itself and by understanding the searchable content. And it further integrates the information from the various content resources. Thus the outcome of same keyword will be more semantically relevant results and no repetition of results. Further the results will be presented in a more direct format; be it a table, a graph or a list. These structured formats are easily consumed by humans and machines alike.
What I explained just now is the eventual aim of semantic search; and the industry has made some substantial advances towards it. Lot of work is going on; major search engines are spending lot of money to semantify the search experience.. this can be seen in google's 'best guess'; abbreviation handing and synonym understanding features.
Its a very active and interesting space. We at Infosys Labs are excited about this and are doing various research and conceptualizing solutions for semantic search. Our research is around text analytics, semantic search and visualization.