A database is defined by the National Library of Medicine as “a structured file of information or a set of logically related data stored and retrieved using computer-based means.” Databases vary depending on subject, content, search features, date coverage and other features. Consult the user’s guide or select the help icon for each database to learn more about the features offered.
Most databases are subject or discipline specific; others cover more than one discipline such as the case with interdisciplinary topics related to Audiology, which may include both the Sciences and Social Sciences. Where to start? It depends on the nature of the topic or clinical question. For example, the MEDLINE database would be a recommended place to start for location of citations/abstracts to peer-reviewed journal articles for a search on Usher Syndromes. For a topic related to engineering such as directional microphones in hearing aids, Inspec or SCOPUS are recommended. For special education related topics such as literacy levels of hearing impaired children, PsycINFO or Education Resources Information Center (ERIC) are examples of databases that would be appropriate.
Databases vary on date coverage of citations to indexed content. Most databases have complete files of citations to publications dating from the 1970s with some containing incomplete files of citations dating from the 1800s or earlier. If complete citation coverage for a specific time period is required it may be necessary to use several databases or to use the print version of a database (called a print periodical index) for complete coverage.
Databases index from various types of content with some being narrow in focus and others indexing from a variety of content types. The MEDLINE database is a highly specialized database that indexes peer-reviewed journal articles from a very select list of approximately 5,000 biomedical journals, using a controlled vocabulary, Medical Subject Headings (MeSH), for indexing of content. Another example of specialized database is ProQuest Dissertation and Theses Global which indexes only dissertations and theses, worldwide, dating from the 1600s to current.
Other databases index from multiple content types ranging from citations/abstracts to peer-reviewed journal articles, trade publications, conference abstracts, dissertations, books, book chapters, book reviews, clinical guidelines, patents, and other works. For example, PsycINFO includes peer-reviewed journal articles, trade publications, books, book reviews, dissertations, and encyclopedias. The Cochrane Library includes citations to systematic reviews, peer-reviewed journal articles, books, conference abstracts, and unpublished literature.
Databases vary on the search features and capabilities offered. For example, some databases may offer advanced search options such as limiting a search to gender, age, type of publication, and humans or animals; others may only offer basic search options. Some databases also index their records using a controlled vocabulary such as the case with MEDLINE. MEDLINE uses Medical Subject Headings (MeSH) which offers the option of identifying appropriate MeSH terms for searches to allow for more precise searching. Another example of a search feature is the ability to search by an author name. SCOPUS offers a specialized author search feature which allows users to search by an author name and retrieve all indexed publications by that author, and to view citing references to those publications. SCOPUS and Web of Science are two databases that offer a cited reference search option. This allows users to locate citing references to a specific publication. This feature is especially helpful if you have an older publication and want to track subsequent research based on the findings noted in the publication.