More and more, the search engines are using a process called Latent Semantic Indexing for categorizing search results. So what does that mean?
In a nutshell, Latent Semantic Indexing (or LSI) involves analyzing a web page to look for related words and phrases that can be substitutes for each other or help the search engine identify what that page is about. For instance, “car” and “automobile” are two words often used for the same object. If you write a web page about your blue 4-wheel drive automobile, based on the principles of LSI, that page could also rank for search terms that include the word “car” even if “car” doesn’t appear anywhere on the page.
This is an important concept to understand for content writers because it means you can play up these related keywords in your content without harping on them.
In the old days, you counted your keywords and tried to write your web pages with a certain keyword density in mind. In other words, the number of keywords per words on the page. You wanted “automobile” to appear 1% to 5% relative to the actual number of words on the page (i.e. 1-5 times for every 100 words on the page). That’s no longer the case.
Instead of counting keyword densities, with LSI you can spread your keyword usage around to all related keywords. You might use “automobile,” “car,” and “vehicle” interchangeably throughout your content, which is more like natural writing anyway.
Latent Semantic Indexing is the future of SEO. It means that writers can get back to being writers again instead of keyword managers.