After you have asked yourself some questions about the source and determined that it's worth your time to find and read that source, you can evaluate the material in the source as you read through it.

• Read the preface--What does the author want to accomplish? Browse through the table of contents and the index. This will give you an overview of the source. Is your topic covered in enough depth to be helpful? If you don't find your topic discussed, try searching for some synonyms in the index.
• Check for a list of references or other citations that look as if they will lead you to related material that would be good sources.
• Determine the intended audience. Are you the intended audience? Consider the tone, style, level of information, and assumptions the author makes about the reader. Are they appropriate for your needs?
• Try to determine if the content of the source is fact, opinion, or propaganda. If you think the source is offering facts, are the sources for those facts clearly indicated?
• Do you think there's enough evidence offered? Is the coverage comprehensive? (As you learn more and more about your topic, you will notice that this gets easier as you become more of an expert.)
• Is the language objective or emotional?
• Are there broad generalizations that overstate or oversimplify the matter?
• Does the author use a good mix of primary and secondary sources for information?
• If the source is opinion, does the author offer sound reasons for adopting that stance? (Consider again those questions about the author. Is this person reputable?)
• Check for accuracy.
• How timely is the source? Is the source twenty years out of date? Some information becomes dated when new research is available, but other older sources of information can be quite sound fifty or a hundred years later.
• Do some cross-checking. Can you find some of the same information given elsewhere?
• How credible is the author? If the document is anonymous, what do you know about the organization?
• Are there vague or sweeping generalizations that aren't backed up with evidence?
• Are arguments very one-sided with no acknowledgement of other viewpoints?