Scholarly vs. Popular Sources (the "When to use a newspaper article reference question")

I just had a very good question from one of my REM 100 students:
"For the term paper are we allowed to use newspaper articles or should we stay clear of them?"

I have often wondered when to use popular sources in papers? The answer is basically, depends on the source's stake in the material and the audience in question.

"To understand this difference [b/w scholarly and popular sources], it may help to recognize that when you write for a departmental class, you are writing for an audience more expert than the common reader. When writing about Republican and Democratic voting patterns on stem cells, science reports from a general interest magazine like Newsweek might be considered sufficiently authoritative. But when you write about stem cells for a Biomedical Engineering class, your teachers and classmates are considered more expert than the average non-scientist reader. For this audience, your sources must have stronger science credentials, must generally be working scientists, not journalists.

Newspapers are not as easy to classify as other sources. Newspapers are not scholarly sources, but some would not properly be termed popular, either. Every source must be questioned for its stake in the material. The New York Post is known for its conservative political bias, for instance, and for its high opinions of Fox television shows (owned by the same parent company). You might be able to trust its sports coverage, but it would not be considered a neutral source for political news. But some newspapers have developed a national or even worldwide reputation for fairness and accuracy. The New York Times, The Washington Post, and The London Guardian are a few examples. On issues of fact, major mainstream magazines such as Newsweek and Time are also generally reliable.

Finally, it’s worth noting that many Internet sources are less reliable than print sources."
-Yale Writing Center