Technical SEO Tips: Latent Semantic Indexing (LSI)

As search engine algorithms move toward their main goal (to help users find relevant information to their queries), you must evolve your SEO strategy to ensure users can find the content you’re creating for them. In the past, search engines determined what results showed up in SERPs based on exact keyword matching. There was no middle ground; either the word was found or it wasn’t. It’s one of the many reasons keyword stuffing was a tactic to rank higher back in the early days of SEO.

Today, however, search engine algorithms are constantly getting better, new ones are being added, and old ones are being updated. It’s the natural process of making it easier for users to find what they want on the internet by typing one, two, or three words into a search bar. And, as we know, Google takes this job very seriously.

But how does the search engine take a few words and return millions of results? Why do search engines return results in a seemingly illegitimate order based on a single phase or word query? The answer: latent semantic indexing (LSI).

What is it?

Latent Semantic Indexing (LSI) Basics

LSI is one of the many steps in the document indexing process for search engines. It was created and implemented in direct response to the days of keyword stuffing, which is a black hat tactic that is now marked as a way to get penalized — sometimes referred to as getting sandboxed — by search engines.

LSI enables search engines to organize documents based on relative “meaning.” What does this look like? Consider the semantically organized list below:


  • How do I brighten my teeth?

Potential topics of documents returned in SERPs:

  • teeth whitening.
  • bleach your teeth
  • brighten your smile ten shades

The topics are related to or have been seen near the query keywords in the results linked from the SERPs. This is the search engine utilizing LSI to present relevant results to users.

How does it work?

LSI takes synonyms and/or words that are used with one another frequently and groups them together on a scale of relevance in regards to the user’s query. In the example above, the query can pull results that are obviously directly related to the query. It also pulls dental services that may relate to teeth whitening, such as: orthodontic (clear braces), teeth cleaning (hygiene), or cavities simply because these terms are used with and around content pertaining to the whitening of one’s teeth. What does this mean? That hardcore keyword focus is becoming less and less important when it comes to ranking on the SERPs.

LSI is the reason synonyms rank instead of direct match keywords. The content that uses synonyms and ranks higher for related keyword queries tends to be marked as adding more value to the user’s query. This isn’t always the case, but it is something to consider when creating new material for your users and your website.

Why is it important to SEO?

What does this mean for content creation? How does LSI affect content strategy and the overall SEO efforts for your site? The end game for your dental website is to turn qualified users into patients. With this in mind, creating content that serves users (potential patients, in this case) in their query journey is a high priority. LSI allows for casting a wider net when creating awareness about your online presence. Your understanding of the patient searching for a dental service based on their knowledge instead of your working medical knowledge becomes more important than ever.

What would your user search when looking for a dentist in their area? What terms would a user enter into the search bar when looking for periodontal therapy? What questions are your potential patients asking? LSI enables the use of synonyms and semantically related words and services on your website to appear in SERPs where relevant to your user’s query. In a nutshell: Google is smarter and more human-like than ever before. Understanding search intent and looking for content that provides value? Check!

LSI is one of many variables search engines consider when they rank and return results. It’s best to see the user and the search engine as a pair. Create content to help your user first, then translate it so the search engine can deliver it to the user.

“Marketing has never been about keywords, it’s about people.”
~ Simon Penson, Zazzle Media

Not sure if your keyword game is on point? Want to learn how to turn users into patients with your dental website? We’re here to help! Give us a call at (972) 781-8861 or email