Latent semantic indexing was originally used in Adsense to make sure that the Adsense ads landed on pages that had a similar themes to the ads.

The search engine algorithm checks the wording on the page and determines the theme of the page. It was only later that Google applied the algorithms to search engine placement. Now it is used by other search engines as well.

After the Adsense program became popular, many website developers decided to create websites just for the Adsense program. Eventually many websites were developed that had only Adsense ads and no content. Visitors were landing on websites that had nothing more than ads.

Google wanted to make sure that the websites were providing a useful service to their customers so in order to overcome the Ad Farm website phenomenon; they decided to use latent semantic indexing for all websites. Google is not the only one using this algorithm.

So what is latent semantic indexing?

Latent semantic indexing is how search engines evaluate websites based on overall theme and use that information to rank you as relevant or as an authority on your subject.

Search engines are becoming more and more sophisticated and moving away from just looking at keywords density to decide if your website is relevant.

Since search engines will rank your website based on overall subject matter, you will need to structure your sentences and paragraphs using semantically linked words.

The words and sentences you will choose will thematically blend with each other and with the search terms entered.

Latent semantic content is about how words are connected thematically to search terms. For example, if the theme of your website is domestic cats, you will not need to use the words “domestic cats” numerous times in your content in order to rank for that term. As an alternative, you can construct content around related topics such as “main coon,” “Persian cat,” or “Rag Doll cat.”

Luckily, Google has a tool you can use to find terms that relate to your main keywords. Go to www.google.com.

Type in ~domestic cat into the search box. Take note of the bold terms that appear.

Another site you may want to try is www.quintura.com.

Type in ~ domestic cat into the search box. Click to search. Take note
of the bold terms that appear. All of these terms are related to “domestic cat.” If you position your mouse over one of the terms you will see more terms specifically related to that term.

The keyword suggestion tools can be very helpful when writing latent semantic content. You will want to find and use closely related variables of your main subject words and use the variables instead of just using the same main keyword phrase throughout your website.

Search engines will tend see you as an expert on all the variables related to the theme of your website. That is a good thing.