Unified Medical Language System® (UMLS®) Basics

SPECIALIST Lexicon and Lexical Tools

The SPECIALIST Lexicon is an English lexicon containing many words from the biomedical domain. Words are selected for lexical coding from a variety of sources including MEDLINE® abstracts, Dorland's Illustrated Medical Dictionary and the general English vocabulary. The majority of the words are nouns.

The lexicon consists of a set of lexical entries. Each entry represents a word (lexical item). The entry covers one or more spellings in a particular part of speech and describes the morphologic, orthographic and syntactic properties of a word.

The lexical tools are a collection of java programs that process natural language words and terms. The lexical tools include a normalizer, a word index generator, and a lexical variant generator. Together the SPECIALIST Lexicon and lexical tools allow users to develop Natural Language Processing programs.