The Design Challenge approach to teaching biology attempts to make the student and instructor focus on the important core questions that drove the development of the knowledge in the first place!
Although I am familiar with the Scientific method, I don't believe I have used the Design Challenge. These two exercises seem to be great ways to get involved with the material. Sometimes just learning this content is not enough and exercises like these can be very beneficial to the students. I am excited to explore more concepts using this exercise.