Forgive me Dr. Oliver, but could you provide me a clear definition of motivation and purpose as you intend them in your article. I'm probably slower than the average bear so it would help me to understand your case study.
What I get out of your case study is another example of the importance of testing. If the test tested the student's understanding of programming concepts then the teachers would have been very interested in being informed by your research. Since the test was on syntax that was what they taught.
Concept questions are much harder to write than fact questions, and are much more subject to discussion. In a recent computer class that I taught, students were asked to identify how the cursor changed when a certain menu choice was made (I didn't write the question). Well who cares? The cursor changes, which is good interface design, and that is that. Well, the test writer cares. They succeeded in writing a question that will not produce an argument about the answer.
Okay, I'm off my soapbox.
One factor you do not address is funding. Isn't funding a factor in most research? Don't the people with the funds have any influence on what is researched?