Keyword stemming is the process of removing all modifiers of a keyword including prefix, suffix, and pluralization until only the root of the word remains. For example, “consulting” and “consultant” would be stemmed to the same root, “consult.” This technique is useful for SEO keyword research because it helps to identify and group similar keywords.
In the example above, a piece of content that advertises an Agile Development Consultant could target searches for both “agile consultant” and “agile consulting.” It is important to understand how searchers construct their search queries so that you create content that attracts clicks from all possible long tail search variants.
Why Consider Keyword Variants
With long tail searches about topics outside of Google’s knowledge graph, exact match keyword usage still seems to matter—if not for ranking, then at least for click-through rate because exact match keywords rendered in bold in search result listings.
Sometimes one variant of a target keyword might have a higher search volume but another might have a better click-through rate in search results. You can test different variations of a page title to find the variant that provides the best click-through rate.
The Problems with Keyword Stemming
It is important to note that while keyword stemming is great for grouping similar keywords, it can also be great at grouping words that aren’t similar. For example, “popular” and “population” both have the same root but do not have similar meanings. It is important to consider search context and intent when stemming keywords into groups.
Keyword Stemming Algorithm
Keyword Clarity uses the Porter Stemmer algorithm. The Porter stemmer algorithm is a rule-based algorithm that progressively stems words in a sequence of five steps. The first step removes plural forms of words. Later steps further modify the words if they meet the relevant criteria.
For example, the word “revivals” would get modified to “revival” in the first step. The fifth step would stem it into its final stemmed form, “reviv.”
Keyword Stemming for Fun and Profit
To see how keyword stemming works in action, try out Keyword Clarity. You can collect automatically import keywords from Google Search Console or paste them in from any source. Happy stemming!