Research Guides: PAL Research Guide: Advanced Search Techniques

Keyword and Subject Searches

When you search by keyword in a database:

you are searching for words and phrases that can be found anywhere in the text of the item record and/or article.
you are not searching for commonly used words parts of speech. Examples include articles, pronouns, and prepositions. Databases do not index commonly used words, which are called stop words. Examples of stop words in databases are: a, an, about, after, all, also, and, any, are, as, at, based, because, been, between, and many more.

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.

Boolean Searching

What is Boolean Searching?

Boolean searching refers to a search technique that uses tools called operators and modifiers to limit, widen, and refine your search results.

Boolean Searching

Boolean Operators: AND, OR, NOT

When used, boolean operators can limit and refine or widen and expand your search. Operators tie your search terms together in different ways.

AND links search terms together.
OR searches for one term or another.
NOT excludes the search term directly following it.

Boolean Modifiers

Boolean Modifiers can further expand, refine, and improve a search. Boolean modifiers include the asterisk, *, (also known as truncation/wildcard searching), (parentheses), "quotation marks".

The asterisk, *, attaches to the stem of a word and searches for any word includes that stem, or the letters before the asterisk. Therefore, you will get results with different endings but all the same stem. See the following example:
- Searching for stat* will return results with the following words:
  - state, states, statute, statutory, statistic, statistics, stats, statistical, and more!
Parentheses, (), are used to encapsulate OR statements. If you want results that return one word out of a group of two or more, you put them between parentheses to ensure that only one of the search terms is returned: (elderly OR aged OR senior citizen).
Quotation marks, "", return exactly what you typed inside the quotation marks. Therefore if you search for "state" you will only get results containing the word "state" (even the plural of 'state will not be included in your search results!).