38. What is Latent Semantic Indexing (LSI) ?


Latent Semantic Indexing, in layman’s terms is the process by which a search engine in general and Google in particular is able to look for websites on the net like a human being would. It can be said that this is a qualitative search method where the search engine looks for relevant material rather than just links that are associated with the keywords. This has vehemently helped users who are digging up the World Wide Web for information about a particular subject or topic. Google has recently started to use and inculcate this new concept.

It was previously used by Google in their Adsense program to locate relevant hits for certain sites and maximize its popularity. In an effort to inculcate LSI in its search rankings Google has recently purchased the company Applied Semantics, whose brainchild is LSI. This method is now gaining humongous importance and popularity and thus many other search engines are trying to opt for the same.

The algorithm which supports LSI scans the keywords of a particular website and then it compares and draws out relations between these passages and keywords. It does so by scanning the other websites which might have a concentration of the same keywords and thus finds out related words, phrases or passages as required by the user. It even goes as far as checking spellings, grammatical errors and even terminology.

In other words it LSI looks into a particular website to see how relevant it is to what the user is looking for, and, it does so with many other numerous sites at the same time and the most relevant websites are shown accordingly.