Sitting in on courses
Tim Kovacs
A PhD is necessarily very specialised: you become an expert on a very
specific topic. Furthermore a PhD is a lot of work and it's tempting
to focus on it to the exclusion of everything else. A research
assistantship is similar. Becoming an expert in one area is good but
at the same time you want to be a well-rounded computer scientist.
You want to be able to talk to (and collaborate with, and rate
proposals from) people outside your immediate area. This is a
lifelong learning process, especially in a fast-moving subject
like computer science.
To become better-rounded you'll have to make time to learn about
things outside your area. Attending seminars and sitting in on courses
are good ways to do this, and your advisor should support you in
this.
We're all busy but you will find it easier to make the time as a PhD
student (unless you are writing up) or RA than when you have some
other full-time job!
Registering for voluntary courses
As a courtesy you may want to ask the lecturer if you can sit in.
You can register for a Computer Science course as a "voluntary unit" so that
you'll be on the mailing list in case of timetable changes or other
announcements. This will also allow you to submit assignments and have
them marked, if you so wish.
It's also possible to register for courses outside CS as voluntary courses by
talking to the department in question.
To sit an exam you would need to make a special arrangement because
the faculty becomes involved at that point.
There does not seem to be any system for recording credits when a PhD
or RA completes a unit but if you are keen to do so it might be
possible.