Boolean Operators You may have heard of boolean searching. Boolean searching means taking separate concepts and combining them in a search statement in order to retrieve information. And Suppose you were looking for information about physical therapy for elderly persons, you would have to form a search statement to tell the index what information to retrieve. If you are looking for engineering information, more than likely Arts and Humanities Abstracts is not going to be very helpful, unless you're looking for fiction written about engineers and engineering. If you are looking for older articles, check to see if the index covers the years you need.
Some indexes only go back a decade or so, especially the electronic indexes.
Often, the library owns the print versions of some indexes, and these print volumes go back much further. Try to determine if you are at the right stage of research to make use of indexes. If you are looking for general information on a subject, you may want to consult an encyclopedia, textbook, or handbook first in order to determine your interests. For example, if you are looking for general information on environmental issues, it would be better to consult an environmental encyclopedia or handbook to narrow your topic. If you searched for information in an index on the environment, you would probably retrieve thousands of articles on a wide range of topics within the broader topic of the environment.