Stemming

Stemming is a function that automatically reduces words to one or more base forms. Stemming is intended to allow words with a common root form (such as the singular and plural forms of nouns or the various tenses of verbs) to be considered interchangeable in search operations. For example, search results for the word shirt will include the plural form shirts, while a search for fishing will also include its word root fish. Fredhopper provides stemmers using statistical and morphological analysis for a variety of Asian, European, and Middle Eastern languages.

Stemming exceptions

There are exceptional situations for which stemming is not desired or stemming rules don't work properly. This is for example the case where the root form has a very different meaning like "glasses" which is stemmed to "glass". Both keywords have a very different meaning and therefore stemming is not desired as it can pollute the search results.

Add a stemming exception

Fredhopper allows for adding these types of keywords to the stemming exceptions list, to add stemming exceptions follow the steps described below:

1. Open the Merchandising Studio
2. Go to System > Search > Linguistic analyzers
3. Click "English Stemmed"
4. Click on English eCommerce Stemmer
5. Click on "Add stemming exception"
6. If you want a specific word to be exempted from stemming just type that word and hit the Apply/Save button. If want to override stemming rules type in word1=word2 (where word1 is the word itself and word2 is its desired stemmed form) and hit the Apply/Save button.

Reindex For stemming exceptions to take effect a reindex is required. This makes sure all new stemming exceptions are properly removed from the search indexes.

Other languages For other languages, adding stemming exceptions works the same way.Go to the "Stemmed" analyzer for the language for which you want to add a stemming exception and choose the eCommerce stemmer to add the exception.