In order to begin your research, try breaking your topic down into keywords and key concepts. Whether you are using the online catalog, the library's periodical databases, or the Web, in order to do effective research you must choose relevant (important) search terms. These words and phrases allow you to retrieve information, and can be used to narrow or broaden your query.
The process of brainstorming for related words and concepts may lead you to narrowing down your topic (making it less general) or to expanding it in some cases. You may use dictionaries, a thesaurus, the Library catalog and databases to find synonyms and subject headings.
Subject headings are used in some databases and catalogs. They are a standardized vocabulary used in that particular database. You might find that two databases use different terms or that there are other terms you might want to use. Below are two articles - one has climate change in the title but the subject headings include global warming and global climate models. The second article has climate change as a subject but you might be interested in also using environmental policy or protection in that database.

