(May 7, 7:00 AM) Question: The design project suggests that the instructor of the subject should sign grades. This suggestion seems to be quite different from the usual practice in which the university registrar produces certified transcripts. Why are we being asked to make such a big change from the usual practice?

Answer: It isn't actually as big change as it seems. Grades come into existence in the professor's office, not in the office of the university registrar. The design has a general goal of moving toward an all-digital, paperless system, so there needs to be a way for the professor to communicate the authentic grade he or she assigns (and also any later, changed grade) to whoever needs that grade--the registrar to prepare a transcript, the student for a job interview, or a graduate school for admission decisions. The exact communication paths are left for you to design.

For whatever design you decide on, you should make a precise statement of what the graduate school is trying to verify, and why their verification plan is likely to achieve their goal. In other words, analyze what they are trusting so that you can follow that with a judgement about whether that trust is reasonable. Put another way, present a careful analysis of the weaknesses of your design, identifying the points at which grades could be modified or forged.

(Apr 30, 9:00 AM) Question: The DP2 assignment asks us to achieve several competing goals. How can I possibly satisfy all of them at the same time?

Answer: Our expectation is that design teams will think through the issues raised by competing goals, and come up with a design that addresses some goals very well and other goals less well. Some teams might decide to completely jettison a goal while others may embrace it; there is no one right solution. You will have to consider which goals are most important and which are technically hard to accomplish. The write-up should point out the design rationale behind the compromises and assess the actual impact of those compromises.

(Apr 29, 1:00 AM) Questions: Can we assume that universities will maintain records permanently? Can we assume there will be a national Public-Key Infrastructure (PKI)? Can we assume that chimpanzees will be given the same legal status as humans?

Answer: To make it realistically similar to most system design projects in the real world, this design project is deliberately under-specified. Under-specification gives different teams the opportunity to try out a wide range of possibilities and think through various trade-offs. So you are welcome to assume anything you find useful, with one important reservation: your assumptions must be reasonable. We expect you to use some common sense, think through the implications of an assumption, and then state it clearly and offer a reasonably compelling justification for it.