February 17

Mythbusting: LSI or Keywords?


When Google reads website content is it looking for target keyword placement, or is it looking for LSI (Latent Semantic Indexing) terms that match the search intent? The prevailing idea from most SEO professionals is that Google is getting smarter and first looking for the latter - content on pages that matches search intent. We conducted an experiment to see what happens if you compare a single target keyword against a page with the target keyword and LSI keyword variations. The result of this experiment is a game changer!

Make sure to read the post till the end as we have an awesome announcement to share with you!

We set up the test like this..

Based on an observation that ranking pages are not overtly repeating the keyword multiple times in the body copy, we made an assumption that a page with LSI terms will outrank a page with higher keyword density.

Latent Semantic Indexing - words that would naturally come up in a conversation about particular topic. For example, if you are having a conversation about a kitchen, LSI would be: sink, refrigerator, pantry,..

Since Latent Semantic Indexing are words that would naturally come up in a conversation, we had to depart from our normal “Lorem Ipsum” Pages and use an actual term that would produce usable LSI. To do this, a keyword phrase was found that had only a few ranking pages but could produce LSI words.

The keyword chosen was for a local service in a remote area and, when searched in quotes, returned just 4 results. Besides, the articles were both published in Google Doc and made public. The only difference between the articles was that instead of repeating the keyword “house demolition”, the second article used the keyword one time, and then LSI terms in the rest of it. Meanwhile, LSI terms were determined by searching “house demolition” using the Keyword Planner and picking appropriate variations.

Here is what we discovered

After running the test, we discovered that the page that uses only the target keyword will beat a page that uses the keyword 1 time and LSI variations the rest of the time.

Final Takeaway

The last week's episode of SEO Fight Club released the studies behind LSI, which proved Latent Semantic Indexing to be a ranking factor. However, it does not undermine the importance of getting the target keyword on the page. You might have heard many SEO experts talk about getting away from using keywords and just use LSI because of Hummingbird or RankBrain. But you need to help Google understand what the page is about in the first place, and Google does that by looking at those on page optimization signals containing your target keyword.

To conclude, don’t put cart before the horse: optimize for keywords first and then LSI your pages. However, don’t get too excited while optimizing for keywords - putting as many of them as humanly possible (keyword stuffing) can lead a site to getting search penalty. Stressing the importance of good quality content, Google’s own Matt Cutts warned webmasters about keyword stuffing: “...all those people doing, for lack of a better word, over optimization or overly SEO – versus those making great content and a great site. We are trying to make GoogleBot smarter, make our relevance better, and we are also looking for those who abuse it, like too many keywords on a page...” 

Good news is that PageOptimizer Pro can tell you exactly which keyword signals to use where and in what frequency on your page. 

Announcement: New LSI Function in PageOptimizer Pro

We are excited to share with you that POP has now LSI built in to the tool!  In addition to providing LSI terms, POP also gives suggestions on which ones to use, where, and how many times.  


POP starts off with a wide set of possible terms and then runs through different filtering processes to get down to terms where LSI (Latent Semantic Indexing / NLP (Natural Language Processing) / TF-IDF (Term Frequency - Inverse Document Frequency) are in relative agreement.  The tool then calculates a “weight” or importance score - the number in the screenshot that is less than 1. The closer to 1, the more important the term. Lastly, the tool counts the number of times you have used the term and compares that to the average usage.

The goal is to show how many LSI words you are using right now versus how many times you might want to use them. Try if for yourself!

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