Most people use keyword searching when using the internet. With keywords, you have the ability to search using natural language, but you also want to be thorough and try using several variations of the concept you are searching for.
Common keyword variations to consider:
You can start with your own knowledge of a concept to build a list of terms, but you will also want to review relevant articles to find new terms you can incorporate into your search.
Try searching the MeSH database before creating a list of keywords. If there is a subject heading for the concept you are searching for, you may be able to use some information from the MeSH page into your keyword search.
Find the section named Entry Terms. Here is what this section looks like on the MeSH page for "Heart Diseases"[Mesh]:
These terms are similar to the name of the subject heading, but they are not subject headings. They are not automatically searched when you use the MeSH term. These are alternate terms, synonyms and variations that you should consider utilizing as keywords.
In the example above, you would want to search for:
You might not use all these terms in your final search, but entry terms are a good starting point for building a list of keywords.
A citation is made up of several fields. When you enter a term into the search field without specifying any other commands, the database will search all of these fields to try to find the terms you searched for.
You also have the ability to specify which field you want to search. Each field has an abbreviation (called "field tags") that are placed at the end of the keyword. For example, if you want to search only the Article Title field, you can enter:
This image displays the visible fields and their abbreviations in a typical PubMed citation:
You can search for the same keyword in the Title and Abstract fields by combining the field tags as [tiab]. These are the only tags that can be combined in PubMed. If you wanted to search the Title, Abstact and Other Term fields for the same keyword, you would need to enter the keyword again to use additional tags:
"preterm infants"[tiab] OR "preterm infants"[ot]
There are other searchable fields that are not visible in the record such as Corporate Author ([cn]) and Publisher ([pubn]). A complete list is available from the National Library of Medicine's PubMed Help file.