What are keywords?
Most databases don't understand the natural language we speak, so pick out the main concepts in your topic to use as search terms. For example, let's say you are writing a paper on the causes of global warming.
The main concepts, or keywords, are
Hint: leave out little words like the or of.
Think of synonyms and variations
In order to do a comprehensive search, think of synonyms and variations of your main concepts
Roget's Thesaurus can help you think of other search terms.
There are three little words that are used as Boolean operators: AND, OR, and NOT.
Think of each keyword as having a set of results that is connected to it. These sets can be combined in different ways to produce different sets of results. You can also exclude certain sets from your results.
The table below explains how Boolean operators work.
|AND combines different terms when both must be present. Use AND to narrow a search.|
|OR combines terms when at least one must be present. Use OR to broaden a search.|
|NOT eliminates irrelevant terms from a search. Use NOT when you want to exclude all records that contain a certain term.|
A basic search would look like this:
global warming and causes
A more complex search using your synonyms:
(global warming or climate change) and (causes or air pollution or carbox dioxide)