Using subject headings in an advanced search can be incredibly helpful in narrowing your search to only relevant results. Simply using keywords can be effective with the right combination of keywords, but subject headings can take this process a step further.
Consider a Discovery search for educational information about dietary supplements and children. You could just try searching for three keywords: education, dietary supplements, and children, but there is a chance that a lot of your articles might not be relevant. This search found 41,000 results, but there is a strong chance that many of those results may not focus heavily on health education.
Compare and contrast with a much more tightly focused search using one subject heading (Health Education), which returns 914 results and ensures that most of them will focus heavily on health education while also including our keywords of dietary supplements and children.
You can use limiters on the right side of the screen (NOT PICTURED) to further limit your results to books or peer reviewed articles.
If you find a good book or article that may give you inspiration for even more subject keywords to try, which you can learn by finding an article or book that looks relevant to you and reviewing the item's record for more subject keywords by clicking on the title of the article. See below the record for the "Education interventions..." article and the myriad of subject keywords you might try from it. (You will probably need to scroll down in the record.)
Even if one is not research the specific subject covered by the article, one might be able to find or "harvest" a lot of good subject keywords to try. We can see from the subject keywords for this article that it might even be possible to create a super-specific search using THREE subject keywords relating to our original research question - maybe Adolescents, Health Education, and Dietary Supplements? However, do note that such a search may be too specific. Sometimes using too many subject keywords together can actually be a bad thing relative to the information you are trying to find. It might be better to just search for subject: Adolescents and subject: Dietary Supplements, omitting health education, or you might try a keyword like "Middle School" with subject: Adolescents and subject: Health Education. Remember that it is up to you to help decide if what you find is relevant to your topic, and if what you're finding is not relevant, you need to adjust your search's subject headings, keywords, or both.
Remember to mix and match subject keywords and general keywords to find more articles, think critically about what you find and whether it works for your topic or helps answer your research question, and don't be afraid to consult a librarian if you need help deciding on, finding, or using a subject heading.
This will almost always be located at the top of the screen in your database. It will allow you to search for subject headings that the database uses. Look for a term like "Thesaurus" or "Subjects" in the database, or ask a librarian to help you find out if the database you've chosen has this feature.
Limiters and keywords provide you with a way to further customize your search according to your topic. If there isn't a limiter that applies to your search or you want to be exceptionally specific (possibly by using one or more keywords), then use boolean operators and the other text entry fields to customize your search. See other sections the "Library Research Tips" guide for further details on effectively searching.