I came across this article while...what else.. surfing the web. It puts Google's LSI 
into basic terms so goofs like me can understand it a little better. Here we go.
LSI: What Latent Semantic Indexing Means for your Website
Author: Will
I would like to simplify Latent Semantic Indexing (LSI). LSI is an anti-spam algorithm. Instead of linking in all of the scholarly papers from those whose job with Google and other companies is to fight spam; I'm going to give you the down and dirty truth of what LSI is and why it is important to not just Google but all Internet entrepreneurs.
First, I’d like to state that there has not been any published “laymen’s” standards for LSI. My self and others have researched numerous interviews from Matt Cutts. Matt Cutts joined Google in January of 2000 and is now head of Google’s Webspam team. You can visit Matt’s blog at Mattcutts.com/blog/ for up-to-date information on how Google is fighting spam.
Since you're reading about LSI and its is not a common phrase I'm going to assume you're familiar with Google's search engine as well as search engine marketing and products such as Google Adwords and Adsense which continue to be a lucrative business opportunities for millions of online entrepreneurs.
Rather than providing quality content some webmasters initially found that spam would get them ranked high in the search engines index which allowed them to earn enormous amounts of pay per click advertising cash.
Spam made it hard for websites that offered information of value to compete with those that catered to what search engine algorithms thought at the time was quality content. This spawned more spammers and outraged those that use search engines.
LSI ensures a websites' content is of value to the online community rather than just repeating a highly searched word or phrase.
Google devoted resources to update the Googlebot algorithm to make a distinction between quality and a spammy website. The words used in conjunction with (semantics or synonyms) a keyword or phrase is in part what search engines look for to determine how beneficial a website's content is.
Latent Semantic Indexing
Google's Adwords and Adsence business model is great because when it works correctly everyone gets paid. If you do a search on "Alligator shoes” that is what you want information on not a site that has the phrase "alligator shoes" in every sentence.
When the search engine returns information from its index that you are satisfied, you go to that website. Said website may give you some insight as to the different styles, type, and origin of the material of the shoe (content of value) but they may not sell shoes so; from that website, you click on an advertisement link to an eStore that sells the shoe and you make a purchase.
Easy as 1-2-3
1. The Webmaster gets paid when you click on an advertisement link while on their website.
2. Google gets paid from the "Advertised site".
3. The Advertised site is paid when you make a purchase.
LSI is here to ensure everyone gets what he or she want when using a search engine it does not ensure everyone who clicks on an advertisement will make a purchase. In addition, it does not ensure you high page ranking, there are many other factors that contribute to high page rank. Since search, engines are one way to get a large amount of traffic it is to your Internet businesses best interest to ensure your content is not viewed as spammy.
Although some websites have slipped through the cracks, LSI makes the search engine marketing playing field more leveled. It is important that you start or rebuild your website with themed content using LSI.
Themed content: Stick with what your website is about. It is important that search engine robots do not get confused when they visit your website for indexing.
Spammy website: over indulgence in keywords or phrases will not come across as quality content.
LSI: use synonymic or semantic terms in your content (terms that are relevant to eachother).
An easy method to determine what content search engine robots consider quality, do a search. The information returned on the right is what you should model (not plagiarize) your sites content after.
Following the best is a good practice.
LSI separates spammy websites from those of quality. LSI is not a myth. Quality content and organic search engine optimization is the cheapest way to achieving higher page rank.
Individuals that do not make or convert their website content within LSI standards will see a slow drop in their search engine ranking and new websites may not be ranked at all.
Article Source: http://www.articlesbase.com/marketing-articles/lsi-what-latent-semantic-indexing-means-for-your-website-205197.html
About the Author:
Will is the developer of ServicesAreUs, the online resource that provides information on Internet Marketing and how it is used to monetize various Internet business opportunities.
for search engine optimization purposes. And no, I am not talking about using Google to help improve your love life. (I know, I know. Bad joke. Sorry.)
