One of the main goals of this course - besides
learning about Web Data Management [CS561] - is to teach you to give good
talks. You will present some papers in front of the class, in the hope that
this experience will prepare you for giving talks at conferences, interview
talks, etc.
You should realize that giving a good lecture
is hard work and requires extensive preparation. Do not underestimate the
amount of time this preparation takes. Not all recommendations apply equally to
all papers and to all speakers, but they provide some guidance in paper
presentation that hopefully you will find valuable.
Remember:
Practice makes perfect.
The essential ingredient for a good
paper presentation is that you thoroughly understand the paper and the
points it is trying to make. Nice slides and a polished presentation are
important, but cannot make up for a lack of understanding. Therefore, I suggest
that you spend a significant amount of time trying to grasp the contents of the
paper you are presenting. This may require reading additional papers as well,
to get a better understanding of the context.
While it is important to understand the
technical details in the paper, the primary goal in this first phase of the
preparation is to understand what the key points are that the paper is
trying to make. What the key points are is
also a question you should evaluate in
the context of the audience for which you are presenting the paper. Also, do
not forget that it is a course, and that therefore for many people your
presentation is their first exposure to the material. This implies that
relatively high-level points are probably of more interest, while low-level
details are most likely going to be lost on your audience.
Experience indicates that the amount
of information that people carry away from a lecture or a presentation is
relatively small. Therefore, it is essential that you very specifically
highlight the key points of the paper. People are most likely to forget the
rest anyways. It is also well-known that the audience is most attentive in the
beginning of a lecture. Attention then drops until the point where the speaker
signals that the end of the talk is near, at which point attention levels rise
again.
Rule 1
You should have a slide very early on that states the key points of the
paper, and nothing else. You should have a similar slide at the end. You should
decide on these slides first before you proceed.
The most common problem with student
presentations is that students go over the paper from A to Z, in the same order
as the written paper, without adding or deleting anything. This is a very bad
idea. A written paper is an archival document, and therefore it tries to be
complete. With an oral presentation, one tries to relate the key points of a
paper to the audience. That requires highlighting those key points, and only
briefly summarizing or deleting lesser points.
Often people are not quite sure what the key
points are, or they cannot make up their mind. They then try to bury the slide
with the key points into an “overview” slide that outlines the
paper or the talk. This is not acceptable. Having an overview slide may be a
good idea, but it is never a substitute for a slide with the key points of the
presentation.
Your presentation should answer (at least) the
following questions:
·
What
is the problem being addressed in the paper?
·
What
is the technique that is being used to solve the problem?
·
How
does this compare with other work that has been done in the same problem area?
·
What
are the major results of the papers?
Once you have gotten past this part, it is now
time to develop the rest of your presentation.
Rule 2
The rest of the talk should be structured such that it elaborates and
clarifies the key points.
If, for instance, the paper claims
to provide some functionality not provided by earlier systems, you should
specifically state what this functionality is, what it is good for, how it is
accomplished, perhaps what the costs are, etc. If the paper does something
better or faster than other systems, you should explain what the new concepts
are that allow it to do so, and quantify the improvement. Throughout your
discussion, you should occasionally return to the key points to make sure that
the audience does not lose sight of the overall context.
People are often tempted to budget time to
various parts of the talk in a way proportional to the amount of time they
spent getting to understand the corresponding part of the paper. This is often
a bad idea, because it may lead to a disproportionate amount of time being
spent on tricky details that do not contribute to the overall goal of getting
your audience to appreciate the paper. Tricky details are far better understood
by reading the paper. Your talk should be sufficiently motivating such that
people actually want to go read the paper to figure out the details. If you do
decide to go into some complicated aspect of the paper, and again, you should
only do so if you consider it essential, you have to explain it in real detail
and budget enough time to give the audience a chance to absorb the level of
detail. There is a big danger here of starting to explain some complicated
aspect of the paper and try to hurry through it because it is not very
important. Of course, nobody understands what you are trying to do. Attempts
like this usually end with the comment ``Well, I know it's complicated, I don't
have the time to explain it all in detail, but I hope you got the idea''. Congratulations,
you just confused everybody.
Many of the papers that we will read in this
course have experiments, measurements, and performance results in them,
"numbers" as the theoreticians say.
Rule 3
You should fully explain the purpose of the experiments, the
experimental setup, the results, and the conclusions to be drawn from these
results.
In other words, you should make sure that it
does not come across as “a bunch of numbers” but as the account of
a scientific experiment. There is nothing worse than throwing up a slide with
some numbers on, and leave it at that.
Rule 4
Your talk should consist of two clearly delineated parts, one in which
you present the paper as if you were the author, and a second one in which you
offer an evaluation of the paper.
The emphasis in the evaluation
should be on the contents of the paper and also, but to a lesser extent, on the
paper's overall structure and presentation. This is also a good place to make
connections with other papers we have read and cast the paper at hand into a
wider context.
Your final slide should summarize
what you felt that the strengths and weaknesses of the papers were, i.e.
provide some sort of critique and elicit a response from the class.
You should allow for approximately 30
to 45 minutes of presentation. In any case, you should allow for questions both
during and after the talk, and also for some discussion after the talk. A good
rule of thumb is to have about one slide per two minutes of talk, although this
is certainly not a universal rule.
Rule 5
Use a big letter size.
There is an important corollary to
this rule. Occasionally you want to use a figure (or a table) from the paper.
You should not do this by copying the figure on to a slide, but by redrawing it
on a size that will be readable by your audience. In particular, units on
graphs or in tables should be clearly legible. If there is too much in a
particular graph in the paper, split it up in two graphs or present only part
of it.
Rule 6
Do not clutter your slides.
There is nothing wrong with a slide that is
three quarters empty.
Rule 7
Your slides should be visually appealing.
Whenever possible, you should use
examples to illustrate your points. A picture is almost always better than
text. Long bulleted lists are boring. Try to distinguish major and minor points
by using indentation, by using boldface, etc. It is a big plus if you do so
consistently throughout your slides. Colours can be very appealing but must be
used with care. You must be consistent.
Rule 8
A single slide should never try to convey more than a single concept.
All slides should have a title that describes
this concept. If the explanation of a concept goes on for more than one slide,
then repeat the title with some qualifier, or with just (Continued)
added to a title. Never start a new idea in the middle of a slide, or try to
convey more than one concept in a single side. Use a new slide instead.
So now you have all your slides ready.
Rule 9
You should do (at least) a couple of dry runs.
Get some people together, preferably
in the room where you are giving the talk, and go through the entire talk, as
if you were giving it in class. Ask somebody to time it, and ask people to make
notes.
You will find that after a first dry-run, you
will want to change a lot. In fact, it is not uncommon for people to change all
of their slides after a first dry-run.
Rule 10
Avoid premature optimization. Get the contents right first, and then
make your slides look pretty.
One final rule.
Rule 11
Get some sleep the night before your talk.
The night before your talk is not
the right time to do all of the above. Sleepwalkers do not make for exciting
speakers.
There is often debate on how much of
the talk you should memorize. Your presentation should be smooth, but at the
same time it should not appear completely scripted. How much of the talk you
have to memorize to accomplish this effect differs from person to person. You
should definitely not have to consult your notes on a regular basis. Ideally,
you should not have to do so at all. It is very useful to completely memorize
the first minute of your talk. Many people are quite nervous in the beginning,
and memorizing the first minute helps them get off to
a smooth start. Along the same lines, you should outline in detail what you are
going to say in the technically complicated parts of the talk, if any. Only the
most accomplished speakers are capable of improvising successfully at such
times.
Rule 12
Make it look like you are having a good time.
Show some enthusiasm for the
subject. Speak loud and forcefully. Do not end your sentences in a mutter. Do
not be afraid to raise and lower your voice, to delineate more or less important
points. Avoid irritating mannerisms, like jingling change in your pocket,
rubbing your chin, or saying “um” and “ah”. A moment of
silence at the right time can do wonders. If you just said something important
or something very complicated, let it sink in for a while before you continue.
Rule 13
Make sure that the audience can always see the screen.
Do not stand in front of it, and do
not block the projection of the slide on to the screen. Especially after
changing slides, people tend to continue to stand right next to the projector.
In a level classroom, you should go stand next to the screen after changing
slides. Some speakers also move around while they are talking, a good idea when
done in moderation. Also, never remove a slide before people have had a
reasonable amount of time to read what is on the slide. Never flip back and
forth between two or more slides.
Rule 14
Do not try too hard to be funny.
Most people are not very funny,
anyways, especially when they are nervous. There is nothing more awkward than
somebody who is not funny and who is trying to be. There is nothing more likely
to throw you off than to have the audience react stone cold after you tried to
make a joke. In general, if something goes wrong during the talk - most likely
something will in fact go wrong - do not let it throw you off.
Rule 15
Look at the audience and seek eye contact with them.
Do not look at the screen, at your
notes, at the slide projector, or away from the audience in any other way. Look
at the whole audience, not just your friends, the instructor, the first row.
You are much more likely to keep the attention of the audience going this way.
An important aspect of giving a talk is dealing
with questions. The first thing you should realize here is that questions are a
good thing. It means that people are listening. It does not (necessarily) mean
that you did a poor job of explaining something. So maintain a positive
attitude to questions and the people who are asking them. Allow the person who
is asking a question to finish his sentence. Quite often, speakers jump in
halfway with their response. It is rude to do so. And you are probably
answering the wrong question. It makes people feel good if you ask them if they
understood your answer. It is also perfectly acceptable to say that you do not
know the answer. Do not try to hide this by not answering the question, and
certainly not by making fun of the question or the questioner.
Example
Here is an example of a presentation.