|November 10, 2004 [posted]|
November 22, 2004 [note added]
|PubMed's® Automatic Term Mapping Enhanced|
[Editor's Note: This enhancement was implemented on November 22, 2004.]
ubMed optimizes searches using a process known as Automatic Term Mapping (ATM). ATM compares terms from the search query with lists of terms: MeSH® (including UMLS® mappings), journal titles, and author names.
If a searcher's query includes an untagged term that maps to a MeSH term, the term will be searched as the MeSH term as well as a Text Word.
For example a search for hay fever translates to:
"hay fever"[MeSH Terms] OR hay fever[Text Word]
In order to augment PubMed retrieval with additional non-MEDLINE citations, a new translation will be implemented if the searcher enters an entry term for a MeSH heading. This translation will include a Title/Abstract search for the MeSH heading associated with the entry term that is limited to citations outside the MEDLINE subset of citations.
For example, a search for the entry term Odontalgia will soon translate as:
("toothache"[TIAB] NOT Medline[SB]) OR "toothache"[MeSH Terms] OR odontalgia[Text Word]
Inverted MeSH entry terms search in the Title/Abstract field in a reversed form without commas as the direct phrase is more likely to be found that way in a citation.
For example, a search for viral arthritis will soon map as:
("infectious arthritis"[TIAB] NOT Medline[SB]) OR "arthritis, infectious"[MeSH Terms] OR viral arthritis[Text Word]
The new translation will retrieve additional citations in PubMed that have not been indexed for MEDLINE, e.g., in-process and OLDMEDLINE (see Figure 1):
Please note: Often, searchers utilize options from the Limits screen that add tagged terms to their strategies, e.g., "humans"[MeSH Terms]. Or, they incorporate tagged terms into their searches with a Boolean AND, e.g., asthma AND humans [mh]. Others may use the Clinical Queries. Even though these examples do not use a specific limit for the MEDLINE subset, they are self-limiting to the MEDLINE subset because they require that the retrieved citations carry a term that is found only on citations in MEDLINE, e.g., MeSH headings, Publication Types. Any search that is self-limiting to the MEDLINE subset will not retrieve additional citations made possible by this change to ATM as it is intended to supplement retrieval with items not in MEDLINE.
For more information about Automatic Term Mapping, see PubMed's Help. For a review of PubMed coverage, see the PubMed Overview, under "PubMed comprises".
PubMed's Automatic Term Mapping Enhanced. NLM Tech Bull. 2004 Nov-Dec;(341):e7.