LSI: Latent Semantic Indexing:
By Ricky Pitcher04 December 2007
LSI is a mathematical algorithm that can be applied to search engines to generate more relevant search results. LSI technology provides a new method of calculating search engine rankings, generally search engines compile results based on relevancy of a website to the keyphrase searched. When a search is run with LSI, associated words to the keyphrase are automatically taken into account, this will see the results presented by the search engine be more relevant, as if the user had typed in more keywords than they did.
In addition to processing searches while considering additional keywords, the relevancy of the keywords are weighted by set parameters. The matrix involved is complex, considering many factors and compiling search results that would have taken several user specifications to generate. LSI represents a better future for search engine use, essentially increasing the value of the user input to search bar, making finding more relevant information with a search engines easier, quicker and more accurate.
Google.com is not currently using LSI in its searches, but has the facility within its search engine for a user to activate it., entering the "Tilde" symbol in a Google search bar before your keyword(s) will instruct Google to run the search using LSI. On a standard UK keyboard the "Tilde" symbol is accessible by holding 'SHIFT' and pressing the '#' key.
Example of use:
Visit Google.comEnter "Tilde" then 'visit london' into the search bar, then click 'search':
The following image shows the outcome of a LSI based search on Google:
When conducting any Google search, the keywords used are highlighted in bold on the results page. In the above picture you can see that I have only entered two search words, but because I have used LSI, five different words are presented in bold. The LSI matrix has identified these keywords as being of relevance to my search and included them as factors when compiling the website ranking in its search results.
The following image shows where the "Tilde" key is located on the keyboard?:The following image shows the location of the "Tilde" key on your keyboard: