Marieke van de Rakt
Marieke van de Rakt is the founder of Yoast SEO Academy and CEO of Yoast. Her favorite SEO topics are SEO copywriting and site structure.
Google can read and analyze texts very well. It understands that walk, walks and walking all boil down to the same thing. Also, Google knows that baby is basically the same as babies. How? By using something called keyword stemming. This gives you the freedom to alternate between different word forms while writing your text. And that’s why we introduced word form recognition in Yoast SEO Premium. So you can optimize your post and we’ll recognize the different word forms like walk, walks and walking. For longer tail keywords, we also recognize the words when you use them in a different order.
So, at Yoast, we talk about word forms, sometimes also about morphology recognition. At the same time, I hear the linguists at Yoast talking about keyword stemming too. And I noticed some SEOs talked about it as well. But what is keyword stemming? How does stemming relate to morphology recognition? And what does it have to do with SEO? I’ll explain all about it in this post.
What is keyword stemming?
Stemming or keyword stemming refers to Google’s ability to understand different word forms of a specific search query. It’s called stemming because it comes from the word stem, base or root form. To give an example: if you use the word ‘buy’ in a sentence, a stemming algorithm will recognize the words ‘buys’, ‘buying’ and ‘bought’ as variations of the word ‘buy’ as well. Some SEOs also differ between stemming and lemmatization.
Google has used keyword stemming in its algorithms for a long time now. The first blog posts about it from SEO experts like Rand Fishkin and Bill Slawski go as far back as 10 years ago. For languages other than English, Google began recognizing word forms much later. In recent years, Google’s algorithm became even more advanced, making exact match keyword optimization more and more outdated.
Help us improve word forms
The recent launch of French and Russian word forms consist of beta versions that we’re improving and expanding as we go. This might mean that we don’t recognize every word correctly. If you find anything that doesn’t seem right, let us know.
If you want to optimize your text for the term ballet shoes, for example, you should be able to use the term ballet shoe as well. Google understands that ballet shoes and ballet shoe are basically the same thing. Our Yoast SEO Premium plugin also recognizes these different word forms in the following languages: English, German, Dutch, Spanish, French and Russian. We’re working hard on adding new languages to this list, so let us know which one you’re missing!
Stemming and word forms
When people talk about keyword stemming or a stemming algorithm,
This article was written by Marieke van de Rakt and originally published on SEO blog • Yoast.