# Keyword Extraction This code deals with identifying keywords in a document, their positions in the document, their important based on [TF-IDF](https://en.wikipedia.org/wiki/Tf-idf) and their grammatical functions based on [POS tags](https://www.ling.upenn.edu/courses/Fall_2003/ling001/penn_treebank_pos.html). ## Central Classes * [DocumentKeywordExtractor](src/main/java/nu/marginalia/keyword/DocumentKeywordExtractor.java) * [KeywordMetadata](src/main/java/nu/marginalia/keyword/KeywordMetadata.java) ## See Also * [libraries/language-processing](../../libraries/language-processing) does a lot of the heavy lifting.