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Medical Physics

Article databases

Using PubMed effectively

Using PubMed effectively

Sometimes when you search PubMed, you find far more articles than you need or expected, or the search results are not as relevant as you'd like. There are a few tips and tricks that can help you harness the power of PubMed and search more effectively.

To create more effective keyword searches, try these 2 minute tutorials:

To learn how to use Medical Subject Headings (MeSH) to find more relevant results, try this 3 minute video:

Use MeSH to Build a Better PubMed Query

More information about subject headings and keywords can be found in the boxes below.

Subject headings - definition

Subject headings: Definition

A subject heading is an assigned word or phrase used in some databases to uniformly describe a concept. Searching using this standardized word or phrase, instead of keywords, means you do not need to worry about synonyms and spelling variations.

Example: The subject heading for cancer in MEDLINE (via PubMed) is the MeSH term Neoplasms. This means that all articles selected for indexing in MEDLINE that are about cancer will be tagged or indexed with this subject heading or a subsidiary one (note: there is a time delay between the addition of records to MEDLINE and their indexing).

Keywords - definition

Keywords: Definition

Keyword (or textword) searching is when we search for words which we expect to find in the title, abstract, or author-defined terms of relevant articles; it is how we typically interrogate web search engines. Draw up a list of words or phrases related to each concept in your research question. When using this technique, you will need to be aware of synonyms and spelling variations.

Example: Keywords (or textwords) for cancer can include cancer / cancers / cancerous / neoplasm / neoplasms / neoplastic / tumor / tumors / tumour / tumours etc.

Comparison table

Subject Headings (SH)


Pre-defined "controlled vocabulary" terms

Natural language words 

Need to know the exact controlled vocabulary term

Need to think of all synonyms, spelling variations, etc.

Less flexible. Not always an appropriate SH available

Quick & flexible way to start exploratory searches

Database looks for subjects only in the subject heading or descriptor field

Database looks for keywords anywhere in the record

Highly relevant results

Generates irrelevant results



Jill Boruff's picture
Jill Boruff
Schulich Library of Physical Sciences, Life Sciences, and Engineering
(Entrance to Schulich Library is via Frank Dawson Adam Building on campus side or from 3450 University Street doors)

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