Like Jeff, I’d also like to think like Penrod, who wonders whether students feel welcome in learning environments and whether or not that affects their performance or involvement as composers in the learning environment. But instead of studying whether or not students feel welcome, I would like to study which pedagogical methods appeal to extroverts and which ones appeal to introverts (that is, I want to know which methods get them to be interested in and engage with the materials as well as their classmates).
Extroverted students will be more engaged by gregarious activities like group work, collaboration, and discussion, etc. Introverted students will be more engaged by more independent activities, like free-writing, individual brainstorming, and conferencing.
We would need notably diverse activities, two groups of students (one introverted, one extroverted; possibly categorized through Myers-Briggs or something equivalent), and a survey system that we could use to collect data and debrief.
Each student would participate in each activity, give feedback as to whether they liked it, felt engaged/inspired by it, etc., using a measurable scale, and then I would look for correlations in the data that would tell me which student type preferred which activity.
This study (which would assume that learning environments favor extroverted students) would be geared toward a hybrid pedagogy that would consist of mixed methods that could be used (in a “happy medium” sort of way) to engage both personality types evenly, and exclude none (also, this study proposal is inspired by the (scientifically-sound) ideas of Susan Cain: http://www.ted.com/talks/susan_cain_the_power_of_introverts.html).