MeSH Vocabulary File Data Used in Conjunction with MEDLINE
The MeSH Vocabulary is available for download at http://www.nlm.nih.gov/mesh/filelist.html. Many MEDLINE/PubMed licensees use the MeSH Vocabulary File to fully take advantage of the hierarchical nature of the controlled vocabulary in their implementations of MEDLINE.
The MESH Vocabulary File is the authority file for MEDLINE. It is used to validate MeSH indexing terms at data entry/input and NLM's PubMed uses translation tables and explodes derived from MeSH in order to enhance search capabilities. These enhanced capabilities are achieved through special programming at NLM which makes possible the following techniques:
- ability to search print see references, non-print see references, and certain data form abbreviations in MEDLINE as though they were the legitimate MeSH Heading; and
- ability to search chemical synonyms in MEDLINE as though they were the legitimate chemical name.
The MESH file is also used to generate the MeSH Tree Number. The tree number data are necessary because they are the basis of the capability whereby MeSH terms are arranged hierarchically by subject categories with more specific terms arranged beneath broader terms. NLM uses this feature so that when MeSH terms are searched in PubMed, the program automatically includes the more specific MeSH terms. For example, a search on Hand will also include records retrieved on: Hand, Fingers, Thumb, and Wrist because those terms are 'indented' under Hand in the MeSH tree structure.