You are here

Lexical Systems & Tools

Project information

LHNCBC's Lexical Systems Group develops and maintains the SPECIALIST lexicon and the tools that support and exploit it. The SPECIALIST Lexicon and NLP Tools are at the center of NLM's natural language research, providing a foundation for all our natural language processing efforts. In general, we investigate the contributions that natural language processing techniques can make to the task of mediating between the language of users and the language of online biomedical information resources. The SPECIALIST NLP Tools facilitate natural language processing by helping application developers with lexical variation and text analysis tasks in the biomedical domain.

Recently, the Lexical Systems Group began a project to enhance the derivational-variants function of the lexical tools. The derivational-variants function uses a set of derivational facts and rules to generate or identify derivational variants of input terms. Derivational variants are words related by a word-formation process like suffixation, prefixation or conversion (change of category). The current derivational variant system has only suffix rules and facts. These rules and facts are hand entered and curated. In order to add suffixation and conversion functionality to the system, the PDM team has developed a method to automatically extract candidate pairs of words that may be derivationally related, which helps automate the creation of rules and facts for suffixation and conversion.

The SPECIALIST Lexicon and Lexical tools are open source and freely downloadable. The 2012 release of the SPECIALIST Lexicon will contain over 462,000 records, representing over 830,000 forms, an increase of over 13,000 records from the 2011 release. Many of the new terms are derived from de-identified clinical records from our own De-identification project and from the MIMIC database.

Keselman A, Massengale L, Ngo L, Browne A, Zeng Q. The Effect of User Factors on Consumer Familiarity with Health Terms: Using Gender as a Proxy for Background Knowledge about Gender-Specific Illnesses ISBMDA 2006: 472-481
Divita G, Browne AC, Loanne R. dTagger: A POS Tagger AMIA Annu Symp Proc. 2006:200-3
Lin J, Demner-Fushman D. The Role of Knowledge in Conceptual Retrieval: A Study in the Domain of Clinical Medicine Proc SIGIR 2006, pages 99-106, August 2006, Seattle, Washington
Demner-Fushman D, Lin J. Situated Question Answering in the Clinical Domain: Selecting the Best Drug Treatment for Diseases Proc COLING/ACL 2006 Workshop on Task-Focused Summarization and Question Answering, July 2006, Sydney, Australia
Humphrey SM, Lu C, Rogers W, Browne AC. Journal descriptor indexing tool for categorizing text according to discipline or semantic type. AMIA Annu Symp Proc. 2006:960.
Zhang S, Mork P, Bodenreider O. Lessons Learned from Aligning two Representations of Anatomy Proc of the First International Workshop on Formal Biomedical Knowledge Representation (KR-MED 2004); 2004. p. 102-108.
Browne AC, Divita Guy, Aronson AR, McCray AT. Language and Vocabulary Tools AMIA Annu Symp Proc. 2003:798.
McCray AT, Browne AC, Bodenreider O. The Lexical Properties of the Gene Ontology (GO) Proc AMIA Symp. 2002;:504-8.
Brown AC, Divita G, Lu C, McCreedy L, Nace D. Lexical Systems: A Report to the Board of Scientific Counselors September 2003 Technical Report to the LHNCBC Board of Scientific Counselors.