HTH SCI 3S03 is an amazing course. Completely PBL but you get to participate in a number of stimulated scenarios and it is really such a great experience. By the end of the course, most notice a marked improvement in their awareness in professional (and personal) communication and the feedback you get from your peers, facilitator, and even your own reflections is very valuable. I'd definitely recommend it.
Pre-req for 3S03:
HTH SCI 2D06 or 2E03 and registration in Level III or above of the B.H.Sc. (Honours) program; or registration in Level III or above of the B.H.Sc. (Honours) Specializations
I haven't taken HTH SCI 3T03 but I know it is very self-directed and PBL. Here are the pre-reqs:
HTH SCI 2D06, 2E03 or registration in Level III or above of the B.H.Sc. (Honours) Specializations
From:
http://registrar.mcmaster.ca /CALEN...12/pg1867.html