When you search by keyword in a database:
Searching by keyword can be a flexible way to find a large number of results. You can use keyword searching as a way to find targeted results: slang, jargon, and new terms work well in keyword searches.
When you search by subject, you are using a term from a pre-defined controlled vocabulary determined by that database. Many databases feature a subject-specific thesaurus of subject terms that relate back to the contents in that database. You will only receive articles that were assigned the subject heading you searched with. For this reason, articles found via subject heading searches can be very reliable. The subject will appear in the record item's subject heading or descriptor field.
Searching by subject can be a very specific way to find targeted results within a specific discipline or research area. This can be very beneficial to your research; however, searching by subject only works if you know which subject terms to search with.
To select keywords to use for a search, start by writing your topic out as a sentence or question. For example:
"How are children impacted by explicit situations in the media?"
There are several aspects to this question. First, extract key terms from the topic question (bold). Then list synonymous or related terms for each - you have a list of keywords to use!
You will learn more about how to combine these terms and how to account for variations in spelling on the other pages of this guide.
Searches can be improved by using subject headings (or terms).
For example, if we did a keyword search for articles on cars we might find a number of relevent documents, but articles that use the terms "autos", "automobiles", or "vehicles" would not be found. However, by consulting the database's thesaurus, or list of subject terms, we can locate the subject heading that would encompass all these terms and then perform our search.