It was a very high priority for us to obtain demographic information about the MOOC participants. We felt it critical to know where students hailed from, in order to better shape the course for them -- structuring forums, noting future subtitle needs -- and to understand the international reach of Democratic Development. (It turns out there were participants from 185 different countries and territories).
How did we attain such high rates of survey responses? To strongly encourage participation in the survey by your students, you can deploy the following strategies:
Message early. Include the link to the survey in the welcome e-mail to students. Invite their participation!
Message often. Include the survey link in subsequent e-mails to students, either in the body or as a post-script. The series of reminders helps because not everyone reads every e-mail.
Integrate the survey into course material. Add in-video questions reminding students to take the survey. At the beginning of some of the early lectures, I added a question where students were asked either to fill out the survey if they hadn't already, or to check the box that they had completed the survey and move on to the video lecture. (Be sure to include the survey URL in the question). It's an extremely effective, but relatively unobtrusive strategy since students will definitely encounter the videos, in contrast to e-mails that they can easily skip over or miss.
Use inviting language. I framed the survey as a communal endeavor, a way to participate in the Democracy MOOC community. It was also underscored as a way for students to benefit their own learning, because the survey would help the course staff shape a better experience "for you, the students."
Use these methods to invite participation in your survey and learn more about your students! The findings can be eye-opening (and sometimes plain amusing).