Making
a scientific presentation
13.1 Introduction
The quality of
presentations in scientific meetings often leaves much to be desired. A number of sources are now available
to help researchers improve their presentations. Some are listed under the
references and additional sources for this chapter. A good scientific
presentation must follow the following three “Ps”. It should be: Planned with care,
Prepared with care and Presented with care. The following sections provide some
useful guidelines, particularly for beginners.
13.2 Planning of the
presentation
In planning a
scientific presentation, presenters need to ask the organizers of the scientific meeting
about: the audience and their level of knowledge and interest in the subject
since the planning of the presentation will be different for a specialist
audience, a generalist audience or a mixed audience; the time available for the
presentation; and the type of visual aids available. Presenters should ask
themselves what the main message (or messages) is that they would like to
convey and how it can be conveyed to the type of audience concerned in the time
allotted.
The manuscript of an
article (as submitted for publication) should not be used as such for a scientific
presentation. The difference between speaking and writing is the same as the
difference between hearing and reading. A reader chooses his own pace; the listener
must accept the pace chosen by the speaker. Listening to the news on television
is different from reading the news in a newspaper. To change a written
scientific paper into an oral presentation, the presenter must follow three “s
words”: Select, Synthesize, and Simplify. Select from the written article the
points to present. Synthesize the information in the article to package it in
the limited time available. Simplify the presentation of the data, so that it
can be easily followed and
understood by the
audience. In the planning stage, the title of the presentation has to be
decided and an abstract has to be submitted to the organizers of the scientific
meeting. A good title can be defined as the fewest possible words that
adequately describe the contents of the presentation.
The Making a
scientific presentation 163
abstract can attract
or put off the audience. The abstract is the part of the presentation that will
be published in the conference programme. A good abstract should be a miniature version of the presentation. The abstract
should be sent to organizers before the deadline and in the format and length
requested
13.3 Preparation
13.3.1 Preparation of
text
In preparing the text
of a scientific presentation:
• Avoid too much detail
and resist the temptation to overload the presentation with information.
• Avoid jargon and
abbreviations, unless they are clear to all the audience.
• Aim at the average
person in the audience.
• Use plain English.
The structure of a
presentation is different from the structure of a written paper. Normally, it should
consist of three parts: introduction, main message and conclusions. The introduction
should tell the audience what the presentation will be about. Where possible, the opening
sentences should capture the attention of the audience. It helps to have
something like a “punch line”, which will alert the audience to the importance
of the subject. The main message should be clear and concise. The usual detail
of a written paper is unsuitable for a presentation. It is generally unwise to
introduce more than one new idea every 2 to 3 minutes. The conclusion should
summarize the main points. Try for a strong finish. Stopping speaking is not
finishing. Leave the audience with a “take home message”.
13.3.2 Preparation of
visual aids: speaking visually
Objectives for using
visual aids It
has been said that we remember 20% of what we hear, 30% of what we see, but between
50% and 75% of what we see and hear (Sorgi and Hawkins, 1985). A Chinese proverb
says “A picture is worth a thousand words”. Visual aids are not an objective in
themselves. They are used to serve one or more of the following objectives:
• holding the attention
of the audience
• presenting the data
in a clear way
• delivering the
presentation without having to read from notes.
164 A practical
guide for health researchers
Commonly used visual
aids include slides, overhead transparencies and computerassisted presentations.
Slides Slides are the commonest visual aid used in scientific
presentations. They can make or break the presentation. Until recently
photographic film slides were very commonly used; now electronic slides
presented as a data show have largely taken over. The basic rules for a good
presentation are the same for film slides and electronic slides. There are
three main types of slide: text slides, data slides (tables, graphs, flow
charts) and figure slides. A mix of text, data and figure slides helps to
maintain the interest of the audience. Text slides are not meant to be read by
the speaker, but by the audience. Lettering should generally be limited to 4
lines and should never be more than 7, including the title. It is advisable not
to use more than 8 words per line. Complicated tables are not visual aids. They
have been described as instruments of torture for the audience. Tables of data
suitable for written publication are highly unsuitable for a scientific
presentation. The term “Railway Timetable slides” is sometimes used to describe
the difficulty with slides showing complicated tables. Do not use more than
seven lines (including title) and four columns in any table. The writing on a
film slide should be easily legible by the naked eye. Use the whole area of the
slide. There is no need to put the data in an outer box. Note in the design of
the table that the transparent area in a film slide is not square but oblong.
Columns are preferably separated by a space larger than the width of the
column. Graphs should replace tables where possible in a visual presentation.
They are better in showing relationships. Preparation of graphs has now been
made easy by computer programs. Four types of graphs are often used: bar or
column charts; curves; pie-charts and scatter graphs.
• Bar charts are better
for lettering than column charts. Avoid overcrowding the slide. The number of bars
should be limited to five to seven. An overcrowded column chart is sometimes called a
“New York Skyline” slide, to emphasize that it is not suitable for presentation.
• No more than two or
three curves can be shown on a slide. Space on the slide should not be wasted.
• The slices of a
pie-chart must not be too numerous nor too small. Three to five divisions are ideal.
• Scatter graphs are
good for slide presentation. They give a clear and simple overview of the
scatter of the data to show relationship.
Making a scientific
presentation 165
• Flow charts should
not be complicated. A complicated flow chart looking like a “subway” map is not
useful for a presentation. A complicated flow chart can be built up in a number
of successive slides. Figure slides of
drawings and pictures, if meant for humour, should be selected with care and
sensitivity to the type of audience. They should not offend the feelings of anyone
in the audience.
Tips in slide
preparation
• A common mistake is
to try to put too much on one slide. As a general rule, no slide should be
shown unless it can be read by the back row of the audience. As a general rule,
lettering on a film slide should be large enough to be read by the naked eye without
projection.
• The shape of a film
slide is rectangular: 36 × 24 mm. The dimensions of the material on the slide
should be prepared with this in mind.
• Upper case letters
are less legible than lower case letters. This is why lower case is commonly used in
direction signs on motorways and on the underground. Our eyes are more accustomed
to small letters in books and newspapers.
• While choice of
colour is a matter of taste and judgement to a certain extent, colour should not be used
for decoration but to improve understanding. Select colours that project well. Popular
combinations are blue and white, and green and yellow. Red text may be more
difficult to read. The number of colours should be limited to what is really necessary
for presenting the data in a clear way.
Computer software
Computer software is
used for preparation of electronic slides for a data show. A widely used program
is Microsoft Powerpoint. The same program can make the preparation of 35-mm
film slides easier and better. The file of slides created on the computer can be sent
as a floppy disk or via a modem to a bureau for creating film slides.
Computer generation
of electronic or field slides offers a number of additional advantages.
The software guides
you through the preparation, provides templates and recommends consistent colour schemes. Preparation of
graphs is easy. Photographs and drawings can be imported from other software
programs. The program allows each slide to have a text note attached and the
slide and note can be printed out on the same paper page to serve as speaker’s
notes. A number of slides can be printed out on one page of paper to be used as
audience handouts. The slides created for a presentation can be viewed and
edited on the computer screen. Slides are saved and can be included in another
presentation. The slides created for a presentation can be viewed in a timed
fashion on the screen and the timing of the accompanying talk can be checked
and adjusted.
166 A practical
guide for health researchers
Overhead
transparencies
The overhead
projector is a natural successor to the chalkboard. It is particularly useful in
presentations to small groups. Overhead transparencies, as visual aids, have advantages
and disadvantages. The advantages of overhead transparencies are that:
• they may not need to
have the room darkened;
• the speaker faces the
audience, allowing better eye contact;
• they are inexpensive
to make;
• they can be made
quickly, using the copy machine or a computer printer with
compatible
transparent plastic sheets;
• overhead projectors
are usually readily available, are easy to set up and are less likely to break
down; a projectionist is not required;
• the speaker can write
directly on the film by a marking pen;
• information can be
built up in a dynamic way by either drawing directly on the
transparency, or by
adding transparent overlays;
• colour can be easily
used The disadvantages of overhead transparencies are that:
• they are not suitable
for large audiences;
• the projected image
is not as sharp as the slide;
• the projector cannot
be put in a projection booth;
• they can give the
impression of being prepared in haste if not carefully revised and
well presented.
Overhead
transparencies are easily prepared. Handwriting does not produce an
elegant transparency.
It gives the impression of last minute preparation. It may be
more acceptable if
the writing or drawing is done during the presentation. A photocopy machine can
produce a nice transparency from the printed output of a word processor. Only
special transparency sheets suitable for a photocopy machine should be used. A
computer printer can print directly on special transparency sheets suitable for
either laser jet or colour ink-jet printers. Note that transparencies need
longer drying times than regular paper. The computer software may allow
printing the transparency as a flipped document, in which the text and pictures
are reversed. The transparency printed in this way is projected face down. This
allows the speaker to write on the back of the transparency during the
presentation. It is easy then to wipe the writing off later without scratching
the original.
Making a scientific
presentation 167
Computer-assisted
presentation The
same computer software that is used to produce 35-mm slides can produce a screen
show of slides, with manual or automatic control over timing between individual
slides. The slide show can be projected directly to the audience. Notebook
computers have a port to allow connection to an external monitor or to a
special projector. Theequipment is rather expensive but it produces a very
elegant presentation, including theuse of moving text and images. However, do
not overuse the animation features as theycan distract the audience and become
annoying. A good presentation is also a simple presentation. Slides can be
easily sorted and their order re-arranged. The technology is rapidly becoming
the standard for the use of visual aids. Before preparing a computer-assisted
presentation check about the availability of the equipment. Since the new
technology is prone to equipment failure, it is advisable to
have a backup of
slides or overhead transparencies. It is better not to try using this new technology
for the first time in an important meeting, particularly in settings which may not
have experience with it.
13.3.3 Rehearsal
The preparation of
the text and of the slides has to take the allotted time into
consideration.
Rehearsal is the key to making sure that you will deliver the presentation without
exceeding the time. Even very experienced speakers rehearse their
presentations. You can rehearse on your own, or with the help of colleagues.
A pleasant average rate
of delivery is not more than 120 words a minute. A word
processor can give
the exact word count of a written presentation. A double spaced
typewritten page is
about 240 words. For a ten minute presentation, plan on no more
than five pages of
double-spaced text.
A general rule is one
slide per minute if the slide contains information, and one
slide every 5-10
seconds if the slide contains only titles, key words, or is designed just to remove
another visual from the screen. The exact time for the non-information slide
will also depend on the amount of script to be covered while it is displayed.
Having to skip slides during the
presentation, because the slides are too many, means that preparation of the
presentation was poor.
13.4 Presentation
The challenge to the
speaker is to hold the attention of the audience. Particularly
when the lights are
dim, the audience can have sweet dreams during a boring presentation (Harvey et
al., 1983).
168 A practical
guide for health researchers
• Get ready
• Speak well
• Manage your slides
• Keep to the time
• Be prepared to answer
questions.
Getting ready
It is always
advisable to check the room where the presentation will be given,
in advance. Check the
podium for the microphone, the remote control for the slide
projection, the slide
pointer and the lights. Provide your slides, properly arranged, or
diskette to the
technician for projection. Speaking well Perfection in speaking is
acquired. It is acquired by practice, by observing good speakers, and by
learning from your own mistakes as well as the mistakes of other speakers. If
you are excited and eager to share, others will warm to you. If the microphone is
to be attached, attach it to the lapel of the jacket or dress, and not to a
movable part such as the necktie. It can produce a distracting background noise
when you move. Look the audience in the eye. It is more effective not to read
your presentation. If, however, you read from a script, the script should be
written for hearing not reading. Prompter cards or prompter slides can help the
speaker to deliver the presentation without having to read. The generally accepted
rate for easy hearing and understanding is not more than 120 words-a-minute, as
indicated above. Pauses in speaking replace punctuation in writing: comma:
break of one second; semicolon: break of two seconds; period/full stop: break
of three seconds;paragraph: break of four seconds. Varying the tone, pitch and
volume helps to maintain the attention of the audience.
Managing slides Mark and number film
slides. If a slide is projected upside down, there are seven possible ways of
showing it again wrongly, before the correct orientation is discovered. The
international convention calls for a spot to be placed in the lower left-hand
corner as the slide is viewed by the naked eye. This should be visible at the
upper right corner when the slide is inserted. Check your slides before the
presentation. Well organized conferences usually have a preview room where this
can be done. Remember the saying that if anything can go wrong, it will. Be
prepared for the possibility of breakdown of visual equipment. It is generally
advisable to start the presentation with the lights on. Keep the lights off
till you complete showing the slides.
Making a scientific
presentation 169
Use “filler” slides
if needed, to avoid having lights on and off during the presentation. But, it may be good
to conclude while the lights are on, to make a strong finish. Do not read the
slides. You can safely assume that the audience is literate and is not blind. An
exception can be made in case of simultaneous translation, so that the translators can
translate the slide which is read. Better still, provide translators with a copy of your text
notes. Do not go back to a previous slide. Insert a copy. The use of two
projectors in parallel, with two screens (dual projection), and two sets of slides is
really only useful when you want to show changes that are difficult to demonstrate unless
two slides are compared side by side. The audience must be given time to look
at both slides. A good rule is never to show two text slides at the same time. Keeping
to time The speaker who
exceeds his allotted time is guilty of gross bad manners. He imposes not only on
his audience, but also on all the speakers who come after him. It is a sign of
poor preparation. Answering questions Answer politely: Do not answer
questions in a dismissive or confrontational manner. Answer knowledgeably.
Remember that “I do not know” is a good answer.
13.5 Guide to how to
give a “bad” presentation
(Based on a humorous
piece by Richard Smith, editor of the British Medical Journal,
2000)
• Forgetting altogether
that you agreed to speak is a good way to make a mess of your presentation. A
variant is to arrive late. Don’t arrive too late because they will simply have cancelled
your session, probably sending a thrill of pleasure through an audience facing
the prospect of five consecutive speakers.
• One way to prepare
for a bad presentation is not to prepare at all. Step up to the platform, open your
mouth, and see what comes out. This is, however, a high-risk strategy because
spontaneity may inspire both your audience and you. Inspiration must be avoided at
all costs.
• A really bad
presentation needs careful preparation. A good piece of advice is to prepare for the wrong
audience. It is much the best strategy to give an overcomplicated presentation
than an oversimplified one.
170 A practical
guide for health researchers
• Be sure to prepare a
presentation that is the wrong length. Too long is much the best. Most of the
audience will be delighted if your talk is too short. But something that is too
long always depresses an audience, even if what you are saying is full of wit and
wisdom.
• Another trick is to
ignore the topic you are given, and speak on a completely different subject.
• You may be able to
enhance your bad presentation by sending the organizers in advance a long and
dull curriculum vitae to read before your presentation.
• Bad slides are the
traditional aid of a bad presentation. They must be far too many, contain too much
information and be too small for even those in the front row to
read. Flash them up
as fast as you can, ensuring that they are in the wrong order with some slides
upside down. Ideally there should be little connection between what you are
saying and what is on the slide.
• The essence of a bad
presentation is to be boring. Anything that isn’t boring will detract from your bad
presentation.
• Never look at the
audience. Mumble your presentation, and preferably read it. A presentation that is
read will usually be satisfyingly bad, but for the full effect you should have long
complicated sentences with dozens of sub-clauses.
• A truly bad
presentation rarely produces any questions. Most people will just want to get away.
If you do get questions, you may have failed in giving a bad presentation. But
all is not lost. By sticking to the basic rules of being boring and
overcomplicated, and by speaking too long, you may still be able to rescue your
bad presentation. The extra rule on answering questions is that under no
circumstances should you really answer them. Once you have finished say, “Does
that answer your question?” If the questioner has the effrontery to say no,
then do it again, only at greater length.
References and additional sources of informationHarvey RF, Schullinger MB, Stassinopoulus A, Winkle E. Dreaming during scientific
papers. British Medical Journal, 1983, 2: 1916–1919.
Hawkins C. Speaking at meetings. In: Hawkins C, Sorgi M, eds. Research: How to plan, speak and write about it. Berlin, Springer-Verlag, 1985: 60–84.
Hextall A, Cardozo L. Presenting a paper. In: O’Brien PMS, Pipkin FB, eds. Introduction to research methodology for specialists and trainees. London, Royal College of Obstetricians and Gynaecologists Press, 1999: 218–224.
Lashford LS. Presenting a scientific paper, including the pitfalls. Archives of Disease in Childhood, 1995, 73: 168–169.
Smith R. How not to give a presentation. British Medical Journal, 2000, 321:1570–
1571.
Sorgi M, Hawkins C. Illustrating talks and articles. In: Hawkins C, Sorgi M, eds. Research: How to plan, speak and write about it. Berlin, Springer-Verlag, 1985: 110–135.
Thompson WA et al. Scientific presentations. What to do and what not to do. Investigative Radiology, 1987, 22: 224–45.
