Using the thesaurus

Audi_insperation; Flickr, Creative Commons Licence: / / /

Top Thesaurus Tips

The key facts 26,142 thesaurus terms in Medline 177,000 entry terms Articles are indexed with the most specific term MeSH updated annually 26,142 thesaurus terms in Medline 177,000 entry terms Articles are indexed with the most specific term MeSH updated annually Source: NLM ( 2011) Brenda-Starr; Flickr, Creative Commons Licence: / /

NLM definition “…sets of terms naming descriptors in a hierarchical structure that permits searching at various levels of specificity” Source: NLM ( 2011)

60 Seconds Start Timer The challenge: How do you describe what a thesaurus term is to users? (in an uncomplicated fashion and in less than 1 minute?) How do you describe what a thesaurus term is to users? (in an uncomplicated fashion and in less than 1 minute?)

Advantages Capture variations on author terminology –E.g. chicken pox, varicella Focus on the content of the article Capture variations on author terminology –E.g. chicken pox, varicella Focus on the content of the article

Choosing the right term Tick the ‘Map to Thesaurus’ and click Search NOT ‘Browse thesaurus headings’

Check the scope

Another reason for checking the scope…

60 Seconds Start Timer The challenge: How do you describe what the ‘explode’ function is to users? (in an uncomplicated fashion and in less than 1 minute?) How do you describe what the ‘explode’ function is to users? (in an uncomplicated fashion and in less than 1 minute?)

Explode Belaph; Flickr, Creative Commons Licence: / / In simple terms, exploding ensures you don’t miss anything indexed on a particular topic Captures all the narrower terms beneath the selected terms – indexers will select the most specific term In simple terms, exploding ensures you don’t miss anything indexed on a particular topic Captures all the narrower terms beneath the selected terms – indexers will select the most specific term

60 Seconds Start Timer The challenge: How do you describe what the ‘major focus’ is to users? (in an uncomplicated fashion and in less than 1 minute?) How do you describe what the ‘major focus’ is to users? (in an uncomplicated fashion and in less than 1 minute?)

Major focus A useful way of narrowing down a search Of the thesaurus terms applied to the record, 4-5 thesaurus terms are selected by the indexer as the describing the major focus of the article Denoted by asterisks on MeSH headings and subheadings A useful way of narrowing down a search Of the thesaurus terms applied to the record, 4-5 thesaurus terms are selected by the indexer as the describing the major focus of the article Denoted by asterisks on MeSH headings and subheadings gerlos; Flickr, Creative Commons Licence: /

Rule of Three More than 3 major concepts: If more than 3 related topics are each presented as a major topic of the article, the more general MeSH heading under which they are all treed is usually designated as the major topic. The specific headings are usually indexed, but not as major topics. More than 3 non-major concepts: If more than 3 related concepts are discussed in an article but are not a major topic, the more general MeSH heading under which they are all treed is usually indexed. The specific headings usually are not indexed. More than 3 major concepts: If more than 3 related topics are each presented as a major topic of the article, the more general MeSH heading under which they are all treed is usually designated as the major topic. The specific headings are usually indexed, but not as major topics. More than 3 non-major concepts: If more than 3 related concepts are discussed in an article but are not a major topic, the more general MeSH heading under which they are all treed is usually indexed. The specific headings usually are not indexed.

Subheadings

Lots of combinations…

What do you do when… There is no relevant thesaurus term? There is more than one relevant thesaurus term? There is more than one relevant thesaurus term that relates to the concept?!!

No relevant thesaurus term…

…or is there?

Definitely no term… Search on your freetext terms

More than one relevant thesaurus term

more than one relevant thesaurus term that relates to the concept…

or/and… Search on your freetext terms

Thesaurus terms may not help you when… Your topic is new or emerging medical concept You suspect there is very little out there You want recently published articles The articles are not indexed in the database Your topic is new or emerging medical concept You suspect there is very little out there You want recently published articles The articles are not indexed in the database Hlkljgk’s; Flickr, Creative Commons Licence:

Top Thesaurus Tips