Evaluating Secondary Sources
There are a series of questions you should ask yourself when evaluating the relevancy, legitimacy, or accuracy of particularly secondary sources. If it is a primary source you are using, an important question may be which edition is the standard or preferred (Kritische Ausgabe, Nationalausgabe, Studienausgabe, etc.). For secondary sources, the questions below are some examples:
Is the piece clearly written? A fuzzy article may mask a meagre content. Do the arguments presented support the conclusions? Are opposing arguments addressed? Is there a critical apparatus (footnotes, bibliography)? Make sure that you verify the citations used. You would be surprised how often citations are either inaccurate, misquoted, or misstated. A book review can be helpful since it offers you the evaluative opinions of others; however, there may very well be biases at work here as well. Think critically. For articles you may wish to consult the Web of Science to see how often an article has been cited.
Is the author an expert in her or his field? What else has the author written? Is the person (or persons) affiliated with an academic institution? This is not to say that "nonexperts" do not offer valuable arguments or that independent scholars are not credible. However, you may wish to be extra cautious.
Sometimes the publisher may not have the best of reputations; for example, Peter Lang and the Edwin Mellen presses. These and some other publishers have been known to publish dissertations without acknowledging this fact and reissuing already published works in a nice package at much higher cost, again without acknowledgement. It does not mean that everything these publishers put out is questionable, but again be critical.
What kind of source is it? A newspaper or journal article? Editorial review refers to the pre-publication process of checking information for legitimacy and accuracy. For example, scholarly journal articles are generally reviewed by a panel of experts (a process known as "peer review"), whereas magazine and newspaper articles are reviewed by internal editors.