|Authority - is the author named? Is the source reputable?
Currency - how recently was the information published?
Relevance - is the information useful to you?
Accuracy - can the information be verified in other sources?
Bias - does the author have a specific purpose or agenda?
Be cautious if you can't find the author's name or credentials. An exception is a magazine or newspaper article written by an unnamed staff reporter. When there is no author given, the authority of the source is based on the reputation of the publisher or producer of the information. What is the author's level of education? Is he or she an authority on the subject? Is the author affiliated with a well-known organization, university, or government agency? For a web page, is it hosted by a reputable organization, or is it someone's personal web page? For original research, is it published in a peer-reviewed journal?
How recently was the information published? For a web page, how recently was it updated? How long ago was the research conducted and how old are the statistics? Don't expect up-to-the-minute statistics for everything because it takes time to compile and publish them, but keep in mind that sometimes the information is published long after it is collected. It is especially important that medical and health information be up to date. You could use an older source for history and background information, but make sure you check more recent sources for new developments.
Is the information useful to you? Just because an article or web page matches the key words you searched for, that doesn't mean it will have information you can use. If you are writing a paper on the effect of home computers on everyday life, you don't need a computer repair manual. Even if the topic matches, it may be written for a different audience. A brief article may not have enough detail.
Can the information be verified in other sources? Is there any proof? Do you know any of the information given to be false? If one statement on a web page is false, the rest is also suspect. Urban myths are often passed around as facts, and facts "everybody knows" may not be true. Look for the original source when possible.
Does the author have a specific purpose or agenda? Is the author trying to persuade the reader to a particular point of view? Be skeptical of a web site that touts the benefits of an alternative medical treatment when it includes a link to buy the product, for example. For a political issue, make sure you get information from organizations or individuals on more than one side of the issue.
ACRAB is just one way of looking at evaluation; we also have a great checklist using CAARP!
These websites have more extensive information and advice on evaluating websites and other sources of information.
St. Louis Community College Libraries
Florissant Valley Campus Library
Forest Park Campus Library
Meramec Campus Library
Wildwood Campus Library