What is Latent Semantic Indexing Analysis?

Google and latent semantic analysis

Rumor in search engine forums has it that Google is giving more weight to latent semantic indexing (LSI) in its latest ranking algorithm update.

What is latent semantic indexing?

LSI means that a search engine tries to associate certain terms with concepts when indexing web pages. For example, Paris and Hilton are associated with a woman instead of a city and a hotel, Tiger and Woods are associated with golf.

Google has been using this concept to determine suitable ads for its AdSense service for some time now. It seems that Google is now also using this concept to improve the quality of its search results.

If you search for a keyword on Google and add a tilde ~ before the search term, then you get an idea of what Google thinks about a search term.

For example, if you do a semantic search for phone, Google returns Nokia as the first result. A normal search for phone returns different results. Adding a tilde to the search term seems to instruct Google to do a semantic search.

Why is this important to your SEO activities?

If Google uses this concept in its ranking algorithm (which is very likely) then its advisable that you don't focus on a single keyword, but on a set of related keywords with your search engine optimization activities.

You should optimize some of the pages on your web site for keywords that are synonymous with the keyword you're targeting.

When you exchange links with other web sites, make sure that you vary the link text to your web site so that it contains different variations and synonyms of your keyword.

Where can I find further information about LSI?

If you're interested in the theories behind this concept, the following pages can give you detailed information:

http://javelina.cet.middlebury.edu/lsa/out/lsa_definition.htm
http://lsi.research.telcordia.com/
http://research.microsoft.com/users/marycz/ht98.htm http://www.cs.utk.edu/~lsi/papers/index.html

Latent semantic indexing helps search engines to find out what a web page is all about. It basically means to you that you shouldn't focus on a single keyword when optimizing your web pages and when getting links.

The web pages on your web site should be related and focus mainly on a special topic while using different words that describe the topic. Use variations of your keyword and synonyms. That makes it easier for search engines to determine the topic of your site.

Tools that help with website promotion...

Search engine news of the week...

Google has updated its index again!

"With any change, there are going to be some sites that move into the first search page and some sites that move out. That's the reality of any change in search engine results."

Editor's note: If you want to adjust your web pages for Google's new ranking algorithm, take a look at IBP's Top 10 Optimizer. Its advice is always up-to date because it's based on the analysis of the current top 10 rankings.