The English department at a local college is considering using electronic-based assignment submission in its English composition classes. To study its effects, each section of the class is divided into two groups at random. In one group, assignments are submitted by turning them in to the professor on paper. In the other group, assignments are submitted electronically.

a. Is this a randomized experiment or an observational study?

b. Assume that the electronically submitted assignments had many fewer typographical errors, on average, than the ones submitted on paper. Could this result be due to confounding? Explain.