Databases can be divided into reference, full text and factual databases. They can be multidisciplinary or they may concentrate on one single discipline or topic area. When running an information search, one should also keep in mind how broad or deep the results should be in terms of, for example, time span or geography.
The choice of suitable database(s) for your information search is affected by many factors. Here are the major factors:
Subject matter
Some databases are multidisciplinary, but others focus on a particular discipline or subject matter. For example, the Web of Science covers a number of disciplines, whereas FishBase concentrates merely on fish species. Often one has to perform searches in two or more databases to be sure that the subject matter is covered.
Reliability of information
When evaluating the reliability of an information source, it is important to establish the background of the source of information. Does it come from a scientific or professional expert, or is it functioning from ideological or commercial considerations? University libraries make their choices about databases with a view to their suitability for gathering scholarly information. The quality of a database can also be assessed by looking to see if, for example, it offers tools for analysis. There is also variation in the quality of references which databases contain.
Time span
There is variation in the time span covered by reference databases. The majority of e-journal databases contain information from the 1990's to the present day. It is also worth noticing how often the database is updated.
Geographic coverage
The geographic coverage of databases varies. For example, the economics database ABI/INFORM is rather US centred, whereas ProQuest European Buisness focuses on Europe.
Availability of material
E-journal databases offer full-text articles, depending upon the terms of the access rights agreement. The availability of the sources contained in the search results from the reference databases (from Oulu University Library or other libraries in Finland, the Internet or abroad) must be checked separately. If only a citation found in a database, with SFX you can see whether the item is available electronically and link directly to the full-text.
Language of a user interface and contents
English is the language for searches in most international databases used at the University of Oulu. References and their abstracts are in English, even though the publication itself might, for example, be in Japanese.
The usability of a database and the available tools
To which fields can one limit a search? Is it possible to combine more than two search terms in a search string? Is it possible to combine results lists from separate searches? Does the database contain an in-built thesaurus? Can references be exported to a reference management program etc.?