From the many volumes and electronic resources that you have access to through the Harvard library system to the many resources available on the Web, finding information has never been easier. But at times, the sheer volume of information available to you can be overwhelming: How will you know which sources to rely on? How will you decide which sources are appropriate for a particular assignment? How can you determine if the data on a website is trustworthy? What's the difference between what a peer-reviewed journal offers and what a website like Wikipedia offers?
Although the most useful sources for a given assignment will depend on the assignment itself, as well as on the kinds of sources generally relied upon in your field of study, there are some universal rules that will help you decide whether to use a source. Once you determine whether a source is worth looking at, you'll still need to figure out what you will do with it in your paper, how to cite the information and ideas you draw from it, and how to avoid plagiarism. When you write for an academic audience, you are responsible for making sure that any information you provide and any ideas you cite come from sources that are both reliable and appropriate for your assignment. The most reliable sources are those that have been vetted by scholars in the field—articles published in peer-reviewed journals and books published by academic publishers.
No matter what you're working on, keep in mind that not all sources are appropriate for your project; just because someone has written something down doesn't mean it is a reliable source. Before you decide to rely on a source, you should evaluate the source and decide whether it is appropriate to use in your paper. You should always determine the qualifications of the author, the purpose of the source (that is, in what context it was created), the scope of the source (what it covers and in what depth), and, where relevant, the currency of the source.