What to Say in a Good Research Talk
John Farrell
Department of
Computer Science
James Cook University
Seminar May 1994
Abstract
Giving a good research talk is not easy. Hints on mechanical
aspects of the speaking process, such as format of accompanying overheads,
behaviour during the talk, and so on, abound, but few authors focus on the
content of the talk; i.e. on the process of designing a good talk in the first
place. I make some suggestions to assist novice and experienced researchers
alike to construct a good research talk. The structure of this paper (though not
the content) is heavily based on the paper by Simon Peyton Jones, John Hughes
and John Launchbury. This is a useful paper, and I recommend that it be read as
a companion to this one.
What This Paper is About
By a research talk, I mean a presentation of
some research work you have done. This work is original to you, and hopefully
original to your audience as well. Thus my basic premise is that you know
something that the audience doesn't, and the purpose of the talk is to tell them
about it. My hypothesis is that if you start by saying the right thing, finish
by saying the right thing, and say all the right things in the middle, you have
given a good talk. Consequently, my guidance is based on choosing how to start,
how to finish, and what to do in the middle.
Where to Start
You must start your talk with something the audience can
understand. In a research talk, this is usually a statement of the problem.
Exactly what you choose as your problem statement depends on your audience.
Generally speaking, your audience will consist of the following types of
people:
- Graduate Students
- Scientists who do not share your research interests
- Scientists who do share your research interests
Graduate students,
depending on the advancement of their studies, probably don't know much about
the forefront of research in your chosen area, nor even a lot of the background,
so to speak to them it would be necessary to identify a well-known problem (we
need to cure cancer, we need to write software that works). Scientists who do
not share your research interests are likely to be familiar with the important
problems in the area, so you are able to choose a less general problem to start
with (we need to discover the structure of a virus, we need to make programs
more readable). Finally, scientists who do share your research interests not
only understand the problem you are trying to solve, but will be familiar with
previous attempts, will have ideas of their own, and may be conducting similar
research. In this case, you may choose a very specialised statement of your
problem (we need to determine when eager evaluation may be substituted for lazy
evaluation without introducing non-termination).
The composition of your audience will depend on the forum - a departmental
seminar is likely to consist mostly of types (1) and (2), an international
conference will be mostly types (2) and (3), and a specialised workshop will be
mostly type (3). In each case, you should choose a different problem statement,
but in all cases it should be a problem that the audience already appreciates to
be a problem. If they agree with your choice of problem, they will be more
willing to listen to your method of solution. If you start by saying something
the audience doesn't believe, they won't believe the rest of what you say
either.
Holtzman [1970] calls the starting point on which everyone agrees the
Common Premise. The more specific your Common Premise is, the less ground
you have to cover to your solution, and the more time you will have to cover
your work in between. Your Common Premise should understood by the majority of
the audience, and believable with a quick explanation to the others. This gives
us the following rule to choose where to start the talk:
Rule 1: Choose the most specific Common Premise suitable to the audience.
Where to Finish
The preponderant tension in construction of a seminar is
between the small amount of time available and the large amount that you could
say about your topic. No matter how fast you speak or how many overheads you
prepare, you will only be able to communicate a limited number of ideas in the
time period, so you should aim to present only that many ideas. If you have
written a paper to go with the talk, put everything you want to say in the
paper; if your talk is successful people will read it anyway. So, as you can't
say everything you want to, you must carefully choose the things you do say.
My technique to achieve this is to choose the single most important thing I
want the audience to learn, and construct the rest of the talk so as to achieve
this single goal. I shall call this goal the Ultimate Idea. The Ultimate Idea
should be characteristic of your work, with the result that comprehension of the
Ultimate Idea gives a listener an understanding of your research.
The Ultimate Idea is not necessarily, and in most cases hopefully not, a
summary of the entire field. Any field which deserves devoted research is too
complex to be summarised in a short talk, and you should not aim to do so.
However, to keep the attention of the audience, the Ultimate Idea should be
novel, unusual or unexpected, and it should be a solution to, or related to a
solution to the Common Premise. It should be an idea which demonstrates the
benefit of research in your field, and your aptitude at carrying it out. We have
the following rule to choose where to finish the talk:
Rule 2: Choose an Ultimate Idea which characterises your work, and
demonstrates progress towards the solution of the Common Premise.
Where to go in Between
Having chosen how to start the talk, and how to
finish it, the structure of the body of the talk becomes obvious - you present
ideas in a sequence which leads the audience naturally and comprehensibly from
the Common Premise to the Ultimate Idea. The most important restriction on this
progress is:
Rule 3: Proceed directly from the Common Premise to the Ultimate Idea. Do
not get sidetracked.
Irrelevant sidetracks will confuse your audience and lose their attention. If
you can't bear to leave a sidetrack out, it is worth presenting in a separate
seminar, but don't clutter up this one!
The key to presenting successful research talks is to keep it simple, even
painfully simple. The people you are speaking to do not have experience with
your ideas and notation, and will not comprehend your ideas instantly. However
if you can present a series of clear steps which lead from a problem to a
solution, your audience will understand and you will have achieved your goal in
presenting the seminar.
We now present a series of ideas which help you achieve comprehension and
credibility.
Assert Your Authority
It is important to assert your authority to talk
on the topic, as listeners not familiar with your work will be wondering whether
you know anything or not. One way to demonstrate your qualifications is to give
a concise and accurate summary of work done on this particular problem. This may
be combined with the Common Premise, by giving a history of work leading from
the general problem to the specific problem that you are addressing. You may
demonstrate that you are familiar with the field by outlining major
developments, and accredit them to known authors in the field. This
``namedropping'' insinuates that you are so familiar with the field that you
almost personally know other researchers.
Of course, if you are a well-known researcher in the field, either your
audience will know you already or you can start your talk with a history of your
own work in the area (``since I proved the Continuum Hypothesis, I have been
investigating...'').
Tell The Truth
In a court of law, witnesses are required to tell ``the
truth, the whole truth, and nothing but the truth''. This is not the case in a
technical seminar, as your listeners are not being paid to hear you speak. The
whole truth is not necessary.
However it is often the case when presenting technical research that the
reasons behind assumptions, proofs, etc, are very complex and require a great
deal of explanation. This explanation should go into an accompanying paper, not
into your talk. If you have successfully established your credibility with the
audience, you can use up some of it by asking them to believe you. However this
is bad practice and should be avoided if at all practical.
It can be sufficient simply to give an intuitive grasp of the reasons behind
your dubious statement (this is called ``hand-waving''). This can be done by
mentioning a related proof which is well-known, or by demonstrating a crucial
part of the proof.
If you can't convincingly avoid this proof, it may be necessary to reconsider
the design of your talk. If the proof is so important, it should probably have a
talk of its own.
Returning to the court room, the requirements that you tell the truth and
nothing but the truth remain. You are giving evidence to an audience which
probably contains experts, and they will be less interested if you do not tell
the truth. Furthermore, they could expose you as a charlatan during question
time.
Rule 4: Tell the truth, but not the whole truth.
A Picture's Worth a Thousand Words
A more fancy and effective method of
hand-waving is by drawing a picture. If an audience can see a graphical
demonstration of why some statement is true, they are likely to believe you
quickly. Furthermore, they are likely to understand the picture far more easily
than they are a proof.
Rule 5: A picture's worth a thousand words, and billions and billions of
Greek letters.
After the Talk
Any good talk deserves questions, and the lack of them is
a sure sign of failure. If you do know what you are talking about, questions are
to be welcomed rather than feared. As Lethbridge [1991] points out, most
questions will be of a curious and sympathetic nature, and demonstrate interest
in your talk. You should answer them with enthusiasm; the questioner may turn
out to be a valuable colleague.
We now examine some common types of questions, and techniques for responding
to them.
Questions about Material You Covered
Some questions will be about
material you did cover in the seminar - the questioner may have misunderstood or
misinterpreted what you were saying. Maybe you covered it too fast, maybe the
questioner has it confused with some similar work.
In any case, this is the sort of question you should be able to answer - you
chose to put the material in your talk, you should be able to explain it. If
only one listener has such a problem, you shouldn't worry. If the whole audience
needs clarification, you should rethink that part of the talk before you give it
again.
Questions about Material You Didn't Cover
Many questions, and in some
ways the most flattering, will be requests for additional detail on areas you
didn't cover due to time constraints. However do not take this sort of curious
question as an invitation to present another five slides!
If the question probes an area of which you do have a wide knowledge, say
enough to satisfy the questioner but not enough to bore the audience as a whole.
You might like to talk to the questioner later.
If the question probes an area which you are unfamiliar with, it is your job
as a reputable researcher to have a reason for not knowing. A standard line is
``I haven't got around to looking at that yet.''
Doubts About Your Common Premise
Some members of the audience may have
doubts about or serious disagreement with your common premise. However relevant
their doubts are, your seminar is not the place to start a debate on the matter
- in your seminar, the Common Premise is taken to be true! With experience in
the field, you will learn the ways in which your Common Premises are attacked,
and you will have to develop ways to answer these questions. While such
questions are not welcome in your seminar, it is your duty as a researcher to
consider their merit, so that you remain convinced that your research is
worthwhile.
Irrelevant Rambling
Occasionally a questioner will take the opportunity
of your question time to sermonise on a marginally relevant topic. In this case,
it is often difficult to discern the question, let alone answer it. Such a
speaker must be diplomatically shut up - the audience is here to listen to you,
not them! Depending on your composure when faced with invasion of your fifteen
minutes of fame, you may promise to ``discuss it later'', or give a short sermon
of your own to assert your occupation of the pulpit.
Conclusion
In summary, you must design the talk for your audience. Start
the talk with something they know, finish it with something they didn't know. In
the middle, say things they understand. At all times, remember that you are, and
act as if you are, an expert in your field.
References
- [Holtzman 70]
- Paul D. Holtzman, ``The Psychology of Speakers' Audiences'', Scott,
Foresman's College Speech Series, Scott, Foresman and Company, 1970.
- [Lethbridge 91]
- Roger Lethbridge, ``Techniques for Successful Seminars and Poster
Presentations'', Longman Cheshire 1991, ISBN 0582869838.
- [Peyton Jones, Hughes & Launchbury 93]
- Simon L. Peyton Jones, John Hughes & John Launchbury, ``How to Give
a Good Research Talk'', ACM SIGPLAN Notices, Volume 28, No. 11, November
1993.