Category Archives: myths

Finally Killing Off Keyword Density

As much as any SEO worth their salt knows that keyword density is not a ranking factor, there are some out there that still believe it is a signal in the Google algorithm or somehow is related to ranking well in Google.

Often this myth is perpetrated by the untrained eye, or sold by the snake-oil salesmen looking to oversimplify the Googe algorithm in the hopes of screwing some SEO noobs out of a few bucks.

This short article’s goal is not to shock you with this amazing new revelation but to provide a single scientifically backed piece of proof that keyword density is to be ignored. This article is a handy link for all the SEO consultants who have clients with notions about keyword density and its importance.

Anecdotal evidence

Let’s think about keyword density and Google’s goals logically.

Google’s goal as a search engine is to provide relevant, useful results to users. That’s why users love Google and keep coming back for more and that’s the only reason Google surged to dominance in the search engine field, not marketing budgets, not clever tricks but providing the best results for search queries.

As a user which would you prefer; a page that consistently and methodically mentions the same keyword or a page that uses a similar word of the same meaning to make the writing sound more natural and flow? The second page right?

So why would Google reward a page that is less useful to users than one that is more useful when that runs against their core goal as a search engine?

They wouldn’t.

Scientific evidence

I recently completed a study of over 12,000 keywords. Comparing data on various search engine factors to the ranking of the top 100 results for each keyword in Google. In total I looked at 1.2 million web pages. I used Spearman’s Rank Correlation Coefficient to compare the data on the various factors I tested with each web page’s ranking in Google.

For example I figured out the keyword density for each of the 1.2 million web pages and compared that with each of those page’s ranking.

Spearman (the statistical measure I used) gives you a number between -1 and 1 representing the nature and strength of the relationship between keyword density and ranking well in Google.

A minus number means there is a negative relationship, i.e. when keyword density decreases, ranking in Google increases.

As that number gets closer to either -1 or 1 the strength of the relationship increases. So a number near zero means there is no relationship between keyword density and ranking well in Google.

As it turns out my study showed that the correlation between keyword density and ranking well in Google is -0.028126693, that means there is pretty much no relationship between keyword density and ranking well in Google and if there is a small relationship then it is a negative one.

But what would a number be without a chart? Let’s compare keyword density’s correlation with some other factors I tested:

Chart: Keyword Density ComparedDescription: Tags: Author:

The final blow

There is no better form of proof than having logic and science confirmed by mother Google. Here’s what Matt Cutts, Google’s #1 webmaster spokesman has to say on the matter – “Keyword Density: Not really a factor. Yes the keyword should be present but density is not important. Include the keyword but make writing sound natural.”

If logic, science and Google all say keyword density doesn’t matter, then it doesn’t matter, so don’t believe anybody who tells you it does and stop hounding your SEO guy/gal about it.