People get worried when they hear about terms such as SEO and LSI, and when they try to find out how to use latent semantic indexing, they get even more worried when they get conflicting messages. On the one hand some say that LSI does not exist and therefore can not be used, while others, on the other hand, state that it is critical to your website's success with the search engines.
We all know what computer people are like, the way they try to make acronyms of everything. LSI is one of these, although not quite what you would call an acronym. LSI does exist, but not in the form that Google would have us believe, and not in any form that you can use to make your website 'LSI compliant'. Anybody claiming that they can do that are simply playing Google's trick and using big names for what is a very simple thing to do.
LSI or LSA?
Without going into any detail as to the mathematical background of LSA, it can be used and is used, to determine the relevancy of a passage of text to any given topic based upon a keyword or multiple word search term. LSA was, incidentally, patented by a group of people in 1988, although the basics were known prior to this. LSI is nothing more than the use of LSA in the indexing and retrieval of information. It is therefore a concept, and you can not make a 'concept compliant' web page.
However, it is all semantics (ha-ha!) And the meat of this article is not to knock holes in the way the terms LSA and LSI are being wrongly used by SEO experts, but inform as to how you can make your web page more likely to be considered relevant to the main keyword for which you want your page indexed. This is very simple and does not warrant all the books being being offered on the subject.
The Development of AdSense
Latent semantic analysis is used by Google primarily to detect spam, in respect of excessive repetition of keywords in order to fool the search engines into providing a high listing for that keyword. There was a time when smart people could indeed achieve this simply by writing a meaningless template with rotating synonyms into which any keyword could be multiply inserted by means of software. Thousand of pages could be generated in minutes, each targeting a different keyword. Some were making $ thousands daily from AdSense using this method.
In fact the principles of LSA to determine the content of web pages were used by a small company called Oingo that changed its name to Applied Semantics who developed a search system to determine the relevancy of page content for specific advert placement. They called this Adsense. This company was in turn bought by Google in April, 2003, and AdSense used to replace their own system which was still under development. Adsense, then, was not developed by Google, …