http://www.nlm.nih.gov/factsheets.dir/coach.html (Einblicke ins Internet, 10/1995)
The Coach Metathesaurus Browser takes queries one or more words long (e.g., "corneal transplantation"; "erythema chronicum migrans") as input. It returns a list of related concepts from the Metathesaurus as output. Its output is ranked using a best-match algorithm based on six elements of the Metathesaurus record plus inverse term frequency. The Browser searches literally hundreds of thousands of elements of Metathesaurus records in a few seconds in these searches. It can show the user why a concept appeared in the retrieval list. It displays Metathesaurus concept definitions, synonyms, lexical variants, and related terms. It displays part of speech and semantic type information. It can display tree structures and child and sibling terms for concepts which came from hierarchically-organized sources.
It offers two views of the Metathesaurus co-occurrence data, a striking and very unusual resource which should be a powerful asset in improving retrieval. Co-occurrence pairs consist of Metathesaurus concepts which were starred MeSH headings (those considered to be among the main concepts discussed in the article) applied to the same MEDLINE record by indexers. The concept-concept co-occurrence display lists in descending frequency order all the other Metathesaurus concepts which co-occurred with the selected concept. The concept/qualifier-concept co-occurrence display presents the initial concept chosen by the user at the top of the screen. Below it is a list of the subheading qualifiers attached to that concept by indexers when indexing articles in MEDLINE. As the user moves down the list of qualifiers, the Coach Metathesaurus Browser assembles and displays lists of the other concepts which co-occurred with the initial concept/qualifier combination. Note that this allows, e.g., the viewing of all the concepts which co-occurred with "Aspirin" when "Aspirin" was qualified by "Therapeutic Use".
The "MeSH information" display presents for terms which came from MeSH online searching notes, previous indexing, history notes, annotation notes, MeSH date of entry, "consider also" terms, entry combinations, associated expressions and the term's postings in MEDLINE and the Backfiles. The "qualifier information" display presents for terms which came from MeSH a list of the subheadings allowed as qualifiers of that term. The circumstances in which each subheading qualifier is used by NLM's indexers is explained in another window as the user scrolls down the list. This should help users understand the likely effect of specific qualifiers in searching. The "chemical information" display presents for chemical terms the CAS Registry Number, related registry numbers, indexing information, pharmacological action, the frequency with which the term was identified in MEDLINE, and the literature sources in which the chemical was identified.
The Coach Metathesaurus Browser and its associated files are being delivered on CD-ROM with the 1993 edition of the UMLS Knowledge Sources. The Browser will run on any AT-compatible computer with 640K bytes of main memory and a color monitor. It requires MS-DOS 4.0 or higher and 125 Mbytes of disk space. Detailed instructions are available from the Coach development team for those users who wish to install the Coach Metathesaurus Browser on a Novell server to make it accessible to entire workgroups on local area networks. This is the method by which NLM delivered the Browser for in-house testing.
For further information, contact
Lawrence C. Kingsland III, Ph.D.
Chief, Computer Science Branch
Lister Hill National Center for Biomedical Communications
National Library of Medicine
8600 Rockville Pike
Bethesda, MD 20894
Internet:
coachteam@nlm.nih.gov
