Most universities require students to fill out end of semester course evaluations. These evaluations are useful in adjusting course design and structure for subsequent semesters. However, these summative evaluations are offered too late in the semester to have any impact on the current semester. Therefore, I recommend that instructors provide students with a chance to complete both formative (early to mid-semester) and summative (end semester) evaluations.
Formative evaluations can be offered to students in the early to mid part of the semester. These evaluations can give instructors the opportunity to discover any serious design flaws or confusing elements in a course, in a timely enough manner to be able to make modifcations to the course. Some students may feel uncomfortable filling out a formative evaluation if it is not anonymous, so in general I recommend providing students with an anonymous discussion forum for providing mid-semester feedback.Summative evaluations can still be quite useful though. These evaluations are excellent for providing feedback on the overall success of a course—its content, organization and delivery.
When designing evaluations, keep them as short as possible to increase the likelihood that students will take the time to fill them out. Also, be sure to separately evaluate the technology, course content and instructor in distinct sections. For example, if distinctions are not clear, students might evaluate content poorly when in reality it was the technology that caused problems. Therefore, it is also important to use terminology that the students understand. For example, I have seen evaluations where students were unclear exactly what was meant by "content," and therefore in the content section they actually evaluated the delivery method. A better term for content might be "course documents" or "course material." The feedback from formative and summative evaluations can be extremely valuable for instructors in determining which components/aspects of a course assist the learning process and which do not.