Computer Laboratory

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Notes on supervising Computer Science

Sean Holden 2011, based heavily on the earlier versions of Frank King.

This document provides some general guidance on the Cambridge supervision system, focusing specifically on the Computer Science Tripos. It is particularly directed at potential supervisors, especially those who have not themselves been exposed to Cambridge supervisions.

Supervisors for all Parts other than Part II of the Tripos are usually engaged by one or more Directors of Studies (DOS) and different DOSs have different requirements and views. Not all will agree with everything which is written here; this is generally regarded as a strength of the system, not a weakness.


Already several potentially unfamiliar terms have been introduced. Here is a glossary.

The Computer Science Tripos

Mainstream Computer Science undergraduates study in the Computer Laboratory for three years. They take a three-Part examination known as the Computer Science Tripos. One Part is taken at the end of each academic year but the Parts are numbered IA, IB and II (not 1, 2 and 3).

The Computer Laboratory, as a University Department, arranges all the lectures and practical classes associated with these courses. Details of all courses are found in the syllabus booklets for the Computer Science Tripos and other documents which you can obtain from the Student Administrator of the Computer Laboratory whose office is GC04 on the ground floor of the William Gates Building.

As well as being a member of the University, each student is also a member of some College. Each College takes a strong interest in the progress of its students and the normal way a College monitors this progress and offers advice and help is through the supervision system. Accordingly, supervisions are formally a College responsibility, although the Computer Laboratory takes on some of the administration for historical reasons explained below.

Directors of Studies

Each College appoints one or more DOSs for each subject in which it has any students. Directors of Studies have two principal tasks. First they must ensure that each student has one or two supervisions a week. They normally give supervisions themselves but they often need to appoint other supervisors too. Secondly, it is DOSs who monitor progress. They usually see each student at the beginning and end of each Term and read supervision reports written by supervisors. It is normal for both students and supervisors to approach a DOS with problems. A student may be experiencing special difficulties with a course or a supervisor may have an ill-matched pair of supervisees.

DOSs distinguish three kinds of supervisor. Those who supervise across a broad range of courses are general supervisors. Others who give advice for just one or two courses are specialist supervisors. Those who supervise projects undertaken by final-year Tripos students are project supervisors.

DOSs often cooperate in syndicates so that several Colleges share in the administration of supervisions. This means that as a supervisor you may be asked by one DOS to supervise students from another's College.

What is a Supervision?

Like an elephant, a supervision is easy to recognise but difficult to define. Whenever you see, almost anywhere in Cambridge, three people, one a little older than the others, sitting at the same side of a desk or table you are probably witnessing a supervision. If the younger ones are clutching lecture notes and old Tripos papers, and the older one is holding forth (see What does a supervisor do?) then you can bet your shirt (er blouse?) on this being a supervision. The one in the middle is the supervisor (formal Cambridge terminology) and the others are supervisees. A past supervisor, Advait Sarkar has written a guide for new supervisors How to define an Elephant which you may find useful

How do you find a Director of Studies to work for?

The Department now asks that all PhD Students and Researchers nominate 5 courses from the Computer Science Tripos which they feel familiar enough with the content to be able to supervise. You will be emailed directly by Student Admin to ask for your choices. This opportunity is now part of the Wiseman Award which encourages students and researchers to share the teaching of undergraduate students by offering supervisions or being a 'ticker' or a demonstrator. This will allow you to share your knowledge and expertise with others, but also to develop your own breath of understanding and build upon skills for your CV. Payment will be made either by the Department (for ticking and demonstrating) or by the colleges for all supervisions.

You can nominate your chosen 5 courses by......

  • Visiting the Student Administrator of the Computer Laboratory or send an e-mail to [Javascript required].
  • Obtain the syllabus booklets and glance at the lists of courses.
  • For courses you might want to cover, take a look at the past Tripos papers to get a feel for the level of the exam questions.
  • Explain that you would like it to be made known that you are interested in supervising.

You can also offer your services to Directors of Studies and the Department via the Computer Science Moodle Match-making site for supervisors and directors of studies in computer science. The Computer Laboratory in general arranges supervisions for the more specialist final-year (Part II) courses. (As the courses are specialized it can be difficult for the Colleges to arrange suitable supervisors. Consequently the arrangement of Part II supervisors was taken over by the Computer Laboratory some time ago).

It is likely that you will quickly find a DOS to take an interest in you. If not, note that most DOSs in Computer Science work in the Computer Laboratory, are friendly and open to being approached. They are likely to know where supervision coverage might be needed.

List of Directors of Studies in Computer Science

What should you ask the Director of Studies?

Once you have the ear of a DOS you will have little further need of this document. The DOS should explain everything you need to know. Nevertheless there are specific matters which need to be clear on both sides and are worth rehearsing here:

  • Explain what your interests are and be clear about which topics you are being asked to supervise. Which year are the students in? Which courses are introductory and which follow on from earlier material? Some of this information will be available in the syllabuses.
  • Ask whether it might be a good idea to attend some lectures yourself.
  • Ask about project supervision. You may decide this is more to your liking than supervising ordinary course work. (Further information on Project supervision is below.)
  • Explain how much time you are prepared to supervise. Three hours a week for each of the 20 weeks a year that courses are run is common. Don't take on too much and allow time for preparing for supervisions.
  • Ask how often you are expected to supervise each group. The answer may vary from 'weekly' to 'just once, it's a very short specialist course'.
  • Make sure you know whom you are supervising and which College or Colleges they come from. Obtain their e-mail addresses.
  • Ask how best to arrange the first supervisions and where to give them. It is very important to supervise where you will not be distracted by the telephone or visitors.
  • Ask about rates of pay and providing reports on students. You should use the CamCORS system for writing supervision reports and claiming for payment.
  • Ask what you are expected to do. The answer may include some of what is written in the next section.

What does a Supervisor do?

Early in both the Michaelmas and Lent terms, the Computer Laboratory runs an informal session for new supervisors. Information about this can be obtained from the Student Administrator, and you are very strongly encouraged to attend. In addition, the Staff Development Office of the University runs a popular course Supervising Undergraduates: An Introduction. The Student Administrator of the Computer Laboratory will have information about this course which is not, of course, run specifically with Computer Science in mind.

Just about the only thing common to almost every supervision is that they are nearly always scheduled to last an hour. Even this rule is often broken for project supervisions where 'a little and often' is sometimes appropriate. The rule should (almost) never be broken the other way; it is most unlikely to profit a supervisee if you take a supervision beyond an hour.

It is also very common to supervise two supervisees at a time. Not many supervisors like supervising three or more at once; the seating arrangements are uncomfortable and it is difficult to treat all the supervisees equally. Colleges don't like the expense of supervising single supervisees but inevitably there will be a few singleton supervisions.

Handouts and other teaching material provided by lecturers can be found in the online course materials, and there is also an archive of past Tripos papers and solution notes. The solution notes for the most recent two year’s worth of examinations are held back by the department and only made available to supervisors and other teaching staff (marked with lock). Supervisors are instructed not to release hardcopy or electronic versions of these notes to students, although they may be shown to students during supervisions when helpful. Older solution notes written by lecturers to accompany past Tripos questions can be obtained from the Student Administrator.

A naive bureaucrat might specify that a supervision should always run as follows:

  • Begin by going through work which you set last time and that the students handed in well before the supervision and which you have carefully read and made comments on.
  • Discuss any problems the students have been having with lectures on the topics you are supervising. Ideally, you should get the students to email such queries in advance, perhaps giving a reference to a point in a course handout (which you should have). You may ask to see the students' own notes and if you can't solve the problem quickly don't waste time struggling in the supervision. Do not have any qualms about leaving a problem until the next supervision. (Alternatively you might email a solution).
  • At this stage you can make your own contribution to the course. Amplify some of the points given in the lectures. Go through your favourite problems. Show how the material relates to other courses and why it is considered important. Generally be enthusiastic and motivating! All this may require some thinking about before the supervision.
  • Sometimes you may want to illustrate points at a workstation or laptop.
  • Draw attention to any exercises included in the course handouts. Urge the supervisees to look at all or most of these and specify questions to be attempted whose solutions you want handed in for next time. It is perfectly in order to invent questions of your own for solving.
  • Towards the end of a course, or after it has finished, you can usefully set questions from past Tripos papers. Don't set anything too frightening too early.
  • Make it clear when and where the next supervision is to take place. Specify exactly what you want handed in, where to hand it in and by when. A good rule of thumb is to ask for work to be handed in 24 hours in advance. This gives you a chance to gain a feeling for how the supervisee is progressing.
  • Keep a log of how many supervisions you have given and to whom. Make notes on how much progress each supervisee has made. At the end of each term you have to write a supervision report on CamCORS about each supervisee and you particularly have to comment on 'ability', 'industry', and 'progress'. Your notes should help you comment accurately.

In practice, it is often unrealistic or even silly to stick rigidly to a plan such as this and your Director of Studies may be the first to say so. For example, supervisees are unlikely to concentrate 100% for the whole hour and if you can predict which part of the plan is likely to be most challenging, arrange to have this early in the supervision. Similarly, you may find that none of your supervisees understands a particular topic and you spend the whole of a supervision covering just one point. This need not be a bad thing. It is better by far to cover a few topics well than several badly.

Finally, while courses on how to teach can be useful, do not forget that the best teachers have often expended considerable effort in developing their own style. Do not be afraid to develop your own.

Supervising Part II projects

The supervision of Part II projects is somewhat unlike other supervisions. Part II, or Final Year, projects represent an extended piece of individual work spread over the third year of the Tripos and accounting for 25% of the marks for the entire degree. The process of completing the project, from a student's perspective, is given in the Pink Book. It may be that during the course of your PhD you find you have ideas that might be suitable for advertising to students as potential projects. If so the best source of advice on how to proceed is likely to be your own PhD Supervisor.

Project supervision tends to be less structured than the supervision of taught courses. Often meetings vary greatly in duration depending on the current degree of progress, the student's overall supervision load and whether they are encountering specific difficulties. The administrative requirements also differ - see the Pink Book for details.

Supervision Nasties

Various things can go wrong. One supervisee may not speak much English, another may hand in no work, a third may turn up too tired or too drunk to take anything in, or not turn up at all. You may suspect a supervisee has social or psychological problems. Quite separately, you may notice that a course seems to be badly given or is being given in a way you think could be improved.

In all these cases you should cope as best you can during the supervision but, at the first opportunity afterwards, report the matter to the DOS. It is not sensible to attempt amateur psychology; DOSs are paid to worry about this kind of thing and may have confidential information which they have not passed to you.

You can probably charge for a supervision which a supervisee missed but it is essential to consult the DOS first.

Sometimes the problem is less immediate. You may notice over time that a supervisee simply isn't keeping up with the work. It may take two or three supervisions to spot an ill-matched pair of supervisees. Once again, let the DOS know.

In practice, not much goes very wrong very often but there is one aspect of supervising which can become a great nuisance and for which your DOS can offer little help. This matter is the subject of the next section.

Arranging and rearranging Supervisions

If it has been decided that you will meet a given pair of supervisees weekly (or perhaps fortnightly) for a Term there is everything to be said for fixing a specific time and sticking to it.

A student's timetable, and indeed your timetable, can easily become very full and if you can find a slot which looks like being free for all of you for a Term, then mark these slots in your diaries in high-grade concrete.

Occasionally a supervisee will have good reason to ask to rearrange a supervision and provided you are warned before the previous supervision you will probably not find it too difficult to find a time suitable to you and both supervision partners. A late warning can result in serious inconvenience; it can be surprisingly tedious to rearrange supervisions by email.

Once in a while you may have to rearrange a supervision because you unexpectedly have to be away yourself. Again, with sufficient notice, a supervision (or perhaps two or three) can be rearranged without too much pain but if you leave the rearrangement too late you can cause inconvenience all round.

Final Advice

Many people find supervising a rewarding business. You can find out how a different side of the Department runs and keep up with the courses. You may find you have some particularly agreeable supervisees who invite you to parties and offer you beer and so on.

Some peripheral aspects of supervising require the exercise of common sense and good taste. If you are in a position to offer your supervisees tea or coffee, this is probably a good idea but handing round stiff gins probably isn't.

Supervisions are a proven part of the Cambridge educational process. Make your supervisions as useful as you can and take advice from your DOS and other supervisors. With any luck, some of your supervisees will achieve high scores in Tripos examinations and you can justifiably claim some of the credit.

Good luck.

Sean Holden, 2011 and Frank King, 1995, 2001. Edited by Student Admin, August 2017