Sometimes a simple checklist will not tell you everything you need to know about a source - especially for unusual formats or document types. This is why it's important to consider sources in context as well as individual pieces of information.
One method for this sort of evaluation is going the three "C"s: Compare, Corroborate and Context.
Compare:
The first step in evaluating a piece of information is to compare it to another source. If you notice differences, you already know you'll need to investigate further.
Corroborate:
The next step is to compare your information to multiple sources; see if you can corroborate the information. In the first step you information may have compared favorably to one other source; however, what if both sources relied on the same study or came from the same research group? Corroborating with multiple sources gives you more points of reference to back up your information.
Context:
The next step is to learn about the context of the information, such as: what's going on with research in the field? What's the mainstream theory or understanding of the topic? Are there other theories or debates about the subject?
Even if a piece of information can be corroborated in multiple sources, there can be more to the story. Maybe the corroborating studies are from a school of thought that has been debunked by mainstream research. Or, there might be two (or more!) separate schools of thought on a topic, both equally valid. Or maybe there is a small amount of new research that contradicts mainstream theories but is potentially more compelling and worthy of further research
You can read more about contextual approaches to resource evaluation in librarian Marc Meola's article "Chucking the Checklist".
