Lemmatizer

A Lemmatizer produces lemmas for each noun and adjective in the document contexts. A lemma is the semantic root of a word that has different inflections. For example, a lemma of geese is goose.

Use the Lemmatizer to match singular/plural and masculine/feminine versions of words.

The output from the Lemmatizer is typically used by other semantic processors in the document analysis chain.

This page discusses:

See Also
Enable Lemmatization with Basis Tech
Ontology Matcher (Resource-Based)
Appendix - Configure Semantic Processors

When to Use

There are two use cases for the lemmatizer query expansion module:

  • If you have configured the Ontology Matcher, Rules Matcher, Fast Rules Matcher, or Semantic Extractor for lemma matches, you must define a Lemmatizer before it in the document analysis pipeline.

  • To perform lemma query expansion for languages tokenized by the Basis Tech (Extended Languages) tokenizer, you must configure the Lemmatizer semantic processor, and follow some additional steps for tokenization.