Stemming is the process of reducing a word to its root form.
When trying to find the best possible match for a given query, we may want to handle cases where for example, the verb
go is written
went in the past tense.
For cases like this, there are predefined algorithms for the Sigmie supported languages.
You can also define your own stemming rules in the Sigmie UI in the Language tab.
Custom stemming rules
If your preferred Language isn't supported by Sigmie yet, you may define your own stemming rules.
You can say for example, that the words
runs should be stemmed down to
Comma separated values
You can use commas to separate the stemming values.
Some cases where custom stemming is a good option are irregular words. For example:
Exclude from stemming
Sometimes an algorithm may be wrong. If for any reason you want to exclude specific words from stemming, you can add them to the Keyword list in the Language tab in your index settings.