Before you start searching the library's collections for good sources, identify about three key words or phrases that represent your topic. Also think about possible synonyms for these terms.
For example, let's say you want to look at the effects of funding cuts to music education in public schools. Your keywords might be: music education, public schools (or elementary schools, secondary schools, etc.), funding (or budget, appropriations, etc.), cuts (or reductions), outcomes (or impact, effects, etc.).
Your keyword list will evolve as you notice other terms that are more commonly used in the sources you find, or that can take your research in a new direction. But your original list will help you decide what to search for, and where.
The library's search tools recognize some words and symbols as keyword connectors. These connectors can be used to broaden or focus your search. Many of these connectors vary from one search tool to another, but there are a few that are almost universal.
The word OR tells the search tool to find sources that include either (or both) of the connected keywords. For example, a search for nittany OR lion would return articles about the nittany lion, along with a report on the geological history of Mt. Nittany, and a review of the Broadway version of The Lion King.
The word AND tells the database to find sources that include both of the connected keywords, which provides more focused results than you would get with OR. For example, a search for nittany AND lion would yield only articles that include both keywords.
However, some of the results of this search may mention Mt. Nittany and reports of lion spottings without ever using the term "Nittany lion." If you want only those articles that include this phrase, wrap it in quotation marks.
For more information on the keyword connectors you can use with a particular search tool, look for a Help link at the top or bottom of the search page.