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Public Health 302

This guide is to work alongside and guide students through the research journal for students enrolled in Public Health 302

Finding Subject Headings

There are several ways to find Subject Headings when you search.

One way to find subject headings:

  • Look to see if the database has an online thesaurus to browse for subjects that match your topic (in PubMed you can actually search for subject terms by selecting MeSH from the dropdown box to the left of the search bar)
  • Some databases publish thesauri in print (e.g. Thesaurus of Psychological Index Terms for the PsycInfo database). Ask Us for help using thesauri.

Another way to find subject headings:

  • Start with a keyword search, using words/phrases that describe your topic.
  • Browse the results; choose 2 or 3 that are relevant.
  • Look at the item and find the Subject or Descriptor field and note the terms used (write them down).
  • You can click on one of those terms to search the database for items on one subject OR
  • Redo your search using those terms.
  • Your results will be more precise than your initial keyword search.

Credits: adapted from MIT Libraries

What is a Subject Heading?

Subject Heading - describes the content of items within a database using what is called "controlled vocabulary"

Controlled Vocabulary - pre-determined terms and words used to classify items within a database so that they can be sorted into subjects.

You can use subject headings to find items on a topic. This can be especially helpful because of alternate terms or spellings for a word, such as Edema, which has formerly--and in some communities is still called--Dropsy, Anasarca, and Hydrops.

How is this different from Keyword searching?

Keyword searching is how you typically search web search engines.  Think of important words or phrases and type them in to get results.
Here are some helpful differences between Keyword and Subject Searches.
Keyword Search Subject Search
Natural language words describing your topic - good to start with Pre-defined "controlled vocabulary" words used to describe the content of each item (book, journal article) in a database
More flexible to search by - can combine together in many ways Less flexible to search by - need to know the exact controlled vocabulary term
Database looks for keywords anywhere in the record - not necessarily connected together Database looks for subjects only in the subject heading or descriptor field, where the most relevant words appear
May yield too many or too few results If too many results - also uses subheadings to focus on one aspect of the broader subject
May yield many irrelevant results Results usually very relevant to the topic

Chart via MIT Libraries

Why Does this Matter?

Subject Headings are super helpful when doing historical research because of the historical changes in names of diseases and conditions over time.

They can also help us pinpoint date ranges, geographical locations, and even social groupings.

For example, if I'm researching historical treatments or writings on Diabetes, I will do a very basic subject search in the National Library of Medicine Digital Collections, but I run a keyword search, then use the Subjects on the left hand side of my results to help me narrow.

I see a of results for quite a few different subjects including General Surgery, Eye Diseases, but "Diabetes Mellitus" does eventually appear as a subject heading, so i select that and I find several posters, a video, and some pre 1900 publications on the topic.

This is one way that subject searching can be useful when doing some historical research. You also have options to narrow and filter by date ranges and geographic areas too the same way you do for subjects.