A database is a collection of information organized for ease of retrieval. They can be multi-disciplinary in nature, or subject-specific. In order to select the best database(s) for your topic, you need to know what's in it compared to what you need to find. Here are three questions to ask about any database before you use it.
What Subject Area(s) Does It Cover?
Note what subject areas are covered to ensure you're selecting the best one(s) for your topic. You may retrieve irrelevant or no articles if you select the wrong databases. If you're not sure about where to start, begin with a multidisciplinary database.
Additionally the choice of databases will influence the type of articles you're likely to find. Articles about Alzheimer's will be very different in medical and science databases when compared to psychology or social work databases.
What Date Range Does It Cover?
Databases vary in the dates covered, ranging from historical to current. Many cover only materials published in the last few decades with a specific cut-off date. Art and Architecture (EBSCOhost), for example, has coverage back to 1921; Nexis UNI includes U.S. Supreme Court decisions as far back as 1790; ERIC includes educational literature from 1966. Databases of historical materials, on the other hand, are unlikely to include contemporary materials.
What Types of Materials Does It Cover?
Most databases index scholarly journal articles, but many include other types of materials in addition to the journal articles. Common materials include: