Does the author agree or disagree with other authors of the subject? Participants and eyewitnesses may misunderstand events or distort their reports, deliberately or not, to enhance their own image or importance.
Roosevelt, as they look at WPA administrators' reports on economic conditions in Pennsylvania and Oregon, or as they listen to recordings of government-produced radio dramas, they weigh the significance of these sources against such generalizations as that provided by Todd and Curti: "The most urgent task that Roosevelt faced when he took office was to provide food, clothing, and shelter for millions of jobless, hungry, cold, despairing Americans.
Essential among these skills is the ability to understand and make appropriate use of many sources of information.
Understand the continuum of history… It is difficult for students to understand that we all participate in making history everyday, that each of us in the course of our lives leave behind primary source documentation that scholars years hence may examine as a record of "the past.
Consider that primary sources about the same event can directly contradict, that they can contain antiquated or complex prose, and that the background knowledge necessary to understand a primary source can be substantial; and it definitely makes sense that your students balk at using them.
Arthur Marwick says "Primary sources are absolutely fundamental to history. Examples in which a source can be both primary and secondary include an obituary  or a survey of several volumes of a journal counting the frequency of articles on a certain topic.
What are the bases of the author's conclusions?