A keyword search will find a word anywhere in a record: the title, abstract, author, text, etc. (the equivalent of searching "everything" in the library catalog). For example, if you search for fast foods and teenage obesity, you'll retrieve results in which all of these four words appear anywhere in the record at least once. However, you won't find articles that use synonyms of these words, such as overweight or youth.
Subject searching uses subject headings that come from a list of terms that have been assigned to articles based on their subject matter. This means you'll need to know which terms have been assigned for certain subjects. For example, if you want to find articles on fast foods and teenage obesity in Academic Search Premier, you'll need to search for convenience foods and obesity in adolescence. This will retrieve all articles that have been assigned these subject headings, even those that use different wording in the text itself.
| Keyword vs. Subject | |
|---|---|
| Natural language words describing your topic. A good way to start your search. | Pre-defined "controlled vocabulary" assigned to describe the content of each item in a database or catalog. |
| More flexible for searching. You can combine terms in any number of ways. | Less flexible. You must know the exact controlled vocabulary word or phrase. |
| Database looks for keywords anywhere in the record (title, author name, subject headings, etc.). | Database looks for subjects only in the subject heading or descriptor field, where the most relevant words appear. |
| Often yields too many or too few results. | If a subject heading search yields too many results, you can often select subheadings to narrow the search. |
| Often yields many irrelevant results. | Results are usually very relevant to the topic. |
Phrase Searches
Use a phrase search to search for certain words as a group. You can do a phrase search by enclosing a phrase in quotation marks to ensure that the database searches for the entire phrase, in the specific order you provided.
Examples of phrase searches: "economic stimulus package," "climate change," "healthcare reform."
Truncation Marks
A truncation mark is a symbol that is added to the end or beginning of the root of a word to
instruct the database to search for all forms of that word. The asterisk
(*) is used in many databases for truncation. Example: adolescen* retrieves adolescent, adolescents, or adolescence.
Think of each search word as having a set of results that is connected to it. These sets can be combined in different ways to create larger or smaller sets of results. You can also exclude certain sets from your results. Boolean operators — AND, OR, and NOT — are the tools you use to combine these sets of results.
The table below explains how Boolean operators work.
| Boolean Operator | Examples | Results |
|
AND
|
children AND poverty |
AND combines different terms when both must be present. Use AND to narrow a search. |
|
OR
|
children OR youth |
OR combines terms when at least one must be present. Use OR to broaden a search. |
|
NOT
|
java NOT coffee |
NOT eliminates irrelevant terms from a search. Use NOT when you want to exclude all records that contain a certain term. |
