The following are answers to typical questions that I receive
frequently, concerning registration in my courses:


Q: I really want to take 15-150 but my grade in Concepts was D.
   Can I take the course anyway?

A: No, I'm sorry.  We require that you have a C or better in 21-127
   (or one of the courses equivalent to it).  That course is important
   for developing mathematical maturity as well as providing you with
   tools useful in many computer science courses.


Q: I would like to take 21-127 concurrently with 15-150.
   Could you please waive the requirement that I take 21-127
   before I take 15-150?

A: I am sorry, but the concepts taught in 21-127 are important
   prerequisites for the type of thinking required in 15-150.
   For that reason I have been advised not to waive the requirement.


Q: I am first on the waitlist for Section B.
   When will the waitlist clear?

A: This is very hard to predict.  Most waitlists clear early in the
   semester, but this is not guaranteed, particularly for section
   times that are in high demand.  In that case, you may need to find
   an alternate section with an open spot.  (See also the answer to
   the next question.)


Q: I am not a CS major and I am 4th on the waitlist for Section F of
   15-150.  I really want to become a CS major and need this course.
   Could you please register me?  Do you know if the course will be
   expanding?  What is the likelihood that I will clear the waitlist?

A: Alas, I have no ability to register you in the course.  The
   registrar has strict capacity rules for the rooms, as required by
   the firecode.  I do not expect the course to expand.  My suggestion
   is to wait at least until the start of the semester.  Some students
   drop during that first week, so something may open up.  Of course,
   the deeper you are in the waitlist, the lower the probability.
   (See also the answer to the previous question.)


I get a similar waitlist question for my other course, 16-811.  My
experience in recent years has been that most students on the waitlist
are able to get into the course by the end of the first week of the
semester, assuming the course is scheduled in a large lecture hall.


I always feel bad saying "no" as I do for some of the above questions,
but there is very little I can do.  (I have discussed these matters
with the dean's office and other administrators involved in registration.)

You as a student probably already know all these answers, I'm
guessing, and are seeking confirmation.  Hopefully this note helps a
little.  If, after reading this faq, you are certain that you should
be registered in 15-150, then please see the appropriate undergraduate
dean's office, both in SCS and your home college.

Best wishes,
Michael Erdmann