For example, you might need statistical data more than journal articles to support your topic thesis. Or, you might find journal articles more helpful than books in researching a very current topic. Once you have chosen your topic, the first step in your research should be to find background information. Background reading provides not only a concise and authoritative overview of your topic, it also can help you focus your topic or shift your attention to an aspect of that topic which is new to you. Importantly, background materials often provide a bibliography or list of other sources for further reading.
Encyclopedias are an excellent source of background information.
Typically, many students skip this step and plunge right into the catalog. Experienced researchers know that it is more efficient to include this step. With a fuller understanding of your subject, you will expand your vocabulary of relevant terminology and search terms. And, with a bibliography of recommended sources in hand, you will be prepared to find pertinent materials in your library. Encyclopedia of Bioethics.