One of the most important aspects of the research process is evaluating the quality of sources to determine their reliability and usefulness. Depending on the topic of your research, you will encounter many types of resources including books, articles and websites to choose from. But not everything you find on your topic will be suitable.

Once you have located your materials, there are a few questions you can ask in order to evaluate the quality of a source:

Authority
Who is the author? What are the author's credentials? Is the author a journalist writing for a popular magazine, or is the author an expert (scholar, university professor) in the particular area being written about? Have you seen the author's name cited in other articles or books on this topic? Is the author associated with a particular organization or institution? What are the goals of this organization or institution?

Who was the publisher? If it is published by a university press or scholarly society (e.g. American Chemical Society) it often indicates that the resource is of a scholarly, rather than popular, nature. When looking for publishing information keep in mind that not all resources are published. For example, resources found on the Web are often unpublished. This does not immediately discredit a source, but it does make it harder to determine the legitimacy of a source.

Purpose/Scope
Scope. What is the breadth of the article, book, website or other material? What is the purpose of the publication? Is it a general work that provides an overview of the topic or is it specifically focused on one aspect of your topic? Does the resource cover the right time period in which you are interested? Is the information being presented as fact or opinion? Are statements supported by evidence? Does there seem to be a bias or slant to the writing?

Audience
Who is the intended audience for this source? Is it written for professionals, consumers, advocates, etc? Is it too elementary or basic? If it is a website, is it sponsored by a company or organization that advocates a certain philosophy? You are more likely to retrieve articles written for the appropriate audience if you start off in the right index.

Currency
When was the source published? Is the date current enough for your topic? Information about research areas in rapidly changing fields, especially in the sciences, often need to be very current, whereas it can sometimes be beneficial to have a somewhat older, more established source when working in the humanities. If the source is a book, is it a latest edition? Library catalogs and periodical indexes always indicate the publication date in the bibliographic citation. If it is a website, when was it last updated? Avoid using undated websites. Does the page include links to other pages to reference or back up information brought up in the paper?