How to give a presentation
SummaryThis article gives some hints on preparing an oral presentation. It is intended for students who have to give such presentations for their courses, but the principles described apply equally well to most scientific and business presentations.
2 Interpersonal factors
3 Structure and planning
6 Visual aids
6.2 Computer and video displays
6.3 Visual cliché
6.4 Grammar and spelling
1 IntroductionUniversities often ask students to give a presentation as part of their coursework. They don't do this because they like to see students squirming nervously (although this is part of the fun) but because the ability to give such a presentation is an important skill, and one that can only be developed by practice. It is a strange fact of human psychology that people like to be told things, rather than reading them. The television and radio news is a good example of this. In principle these are a terrible waste of bandwidth: the same information as delivered by a radio newsreader in ten minutes could be conveyed in an e-mail message in about half a second, and read in about 30 seconds. This gives an important clue to a successful presentation. The listeners don't merely want to be informed, they want to be entertained and stimulated as well. That's why those presenters who simply read from their notes are so boring: the listeners could read the information themselves in a fraction of the time. This article gives some ideas about making a successful presentation. There is much in here that is biased and opinionated, but I hope it is biased and opinionated in a practical sort of way. Talking to groups of people is, after all, one of the main ways in which I make a living.
2 Interpersonal factorsIf you are the sort of person who is unnerved by speaking in public, then you should remember this: the listeners are on your side. Everyone wants your presentation to be good, and will sympathise if you make a mistake or forget what you wanted to say. If your presentation is being marked, the person marking wants it to be a success as well. No, really. So the listeners will start off on your side, and provided you do nothing to antagonize or offend them they will probably remain on your side. Unless you are a professional public speaker, your presentation will probably not be faultless, and you should not expect it to be. Occasional slips will not offend the audience. I have always been surprised at how tolerant people are of my mistakes when I am making a presentation. I frequently forget what I want to say, fidget, curse, turn my back on the audience, trip over, fail to get the visual aids to work, and generally do all the things that experts say to avoid, and yet people still applaud at the end and say they enjoyed the talk. If you give the impression that you are taking the audience seriously, want to tell them something interesting, and have made some effort to prepare, people will be quite forgiving. The more the listeners feel they are part of the proceedings, the more they will be entertained. For this reason, most experts suggest that the speaker should maintain eye contact with the audience. Some beginners take this too literally and stare intently at the listeners, which can be a bit discomforting. If you watch people talking in a social situation, you will see that people make and break eye contact every few seconds. Here are a few other suggestions for keeping the audience involved.
- Make sure everyone can hear you, and see any visual material you are using. If in doubt, ask. (The inevitable response to ''Can everyone hear me?'' is ''Pardon?''. This is not altogether a bad thing; people always laugh even though they've heard it before.)
- If appropriate, ask questions of the audience.
- If people in the audience look blank, ask if you need to explain something again. No-one ever says 'yes', but people like to be asked.
- The occasional joke can be quite useful, provided it is in context. You should probably not rehearse jokes into your talk, as they will sound contrived.
- vulgar and inappropriate humour;
- swearing and blasphemy;
- telling weak jokes and laughing out loud at them;
- appearing to be bored or otherwise showing disrespect to the audience;
- overstaying your welcome (that is, talking for much longer than was expected).
3 Structure and planningWhen planning your presentation, bear in mind that most people have an attention span of about ten minutes for subjects in which they aren't particularly interested. Mine is even shorter than that. You should not expect people to be able to concentrate for longer than ten minutes without some change of subject or method of delivery. The issue of timing is discussed in more detail below. If your presentation is poorly structured or difficult to follow, people won't be able to concentrate even for the ten minutes they normally manage. This means that you need to have a very clear structure to your presentation, so that the audience knows how it is progressing. A good general plan might be something like:
- 10% - 20% introduction;
- 60% - 80% main body of talk;
- 10% - 20% conclusion or summary.
4 TimingThe shorter the talk, the longer it will take to prepare. This is because it is harder to say everything you think is important in the given time. Most business and many scientific presentations have to be limited to about ten minutes. In my experience, the majority of beginners tend to over-run, so keeping to time is a way to make a good impression. There is only one foolproof way that I have found of keeping to time: prepare your presentation on the basis that you have even less time. For example, for a ten-minute presentation I would aim for eight minutes, on the basis that I usually over-run by about 20%. On the whole I disapprove of having a clock in front of me during a talk; I like to practice until I get the timing spot on. If you find that you are running out of time towards the end of a presentation, you should decide which of these emergency measures you wish to take:
- talk a bit faster;
- miss some material out and skip to the end;
- a combination of both the above.
5 PreparationThe most common problem with student presentations is that the presenters underestimate how long it takes to prepare and practice. I find that it takes me a whole day to prepare a ten minute talk. I usually want to rehearse the whole talk about ten times before I feel ready to deliver it. In my experience, the shorter the talk, the longer the preparation. This may seem strange, but if you have only a short time you have to think much more carefully about what to include and what to leave out. You should practice the presentation at least once in front of another person, who should ideally be as critical as possible.
6 Visual aidsMost people who give talks like to support them with visual material, usually slides. You should take the same trouble with the preparation of these as you do for the spoken material. Bear in mind that your visual aids should support the presentation. They should not duplicate what you are saying, and you should avoid the temptation to read them to the audience. 6.1 Slides
A talk with slides is the usual way of presenting scientific results and business plans, so it is important to be familiar with this type of presentation in particular. You need first to decide how many slides you will show. For a short talk I find that one a minute is about right. For a ten minute presentation, I will normally produce ten slides with the most important information on, and another two or three with supporting material. I normally try to anticipate the sorts of questions that people will ask, and prepare supporting slides to illustrate my answers to these questions. Usually I find I don't need all these extra slides, but it doesn't take long to make them. For a one-hour presentation you can take things a bit more slowly; in this case one slide every two or three minutes is probably about right. Of course you should not follow these guidelines dogmatically; if you find you need to show more slides then that's what you should do. If a slide contains complex experimental or statistical results then it will take longer to explain. In this case you may find you can only show a few slides in a ten minute presentation. The trusty old overhead projector is the normal method of showing slides in the academic environment. A common mistake is for the speaker to stand in front of it and obscure the audience's view. Sometimes the projector and screen are deployed so badly that it is impossible to avoid blocking someone's view. If you cannot do anything about this, you should at least apologise for it. On the whole it is possible to convey more information on colour slides than monochrome ones, but it may be that it isn't worth the extra effort to produce them. On an overhead projector slide, good text sizes are about half an inch for ordinary text and one inch for titles. If the slide is about eight inches high, this means you should expect to get about seven lines of text on a slide. The 'rule of seven' states that people are best able to assimilate an image that has about seven entities in it, so this is a good size from a readability and a psychological standpoint. If you photocopy slides from pages of a textbook or other printed material, you can be sure that hardly anyone will be able to read it. 6.2 Computer and video displays
It always comes as a shock to some people, but let me make this very clear: people won't automatically be impressed if you use the latest high-tech visual gadgets. In fact people will be disappointed if you do no more than you could have done with plain slides. The disappointment will be compounded if you waste the audience's time getting the equipment to work. Most conference venues and some university lecture rooms now have built-in video projectors and computers. You should check in advance that the equipment will be compatible with the software you use. I have seen presentations fail to start at all, because the presenters prepared their visual material on computers with very high resolution screens. When transferred to the much lower resolution of the video projector the material did not fit on the screen. The solution is simple: check before you go, and take back-up material in case it doesn't work. Some university audio-visual services will lend video projectors to students for giving presentations. However, you will get no sympathy if it fails to work on the day. There are also slide projectors (as opposed to overhead projectors). In a professional presentation I always carry 35mm slides and a standard projector. First, I can carry a projector with me and be sure it will work, but I don't normally have to, as one is usually provided at the venue. Second, it's very quick to change slides, and they won't fall on the floor or get stuck together. Using a computer with a video projector is easier and cheaper, but I've been let down by this technology far too often to rely on it when it really counts. If you do use computerized visual aids, you can do all sorts of clever things, like animations. These can be a very powerful method for illustrating complex points, but you should probably not use them just because you can. With computer displays it is even harder to avoid 'visual cliché', as will be discussed below. 6.3 Visual cliché
If you only produce presentations occasionally, you may feel the urge to over-produce the visual material, using all sorts of fancy graphics and symbols. I suggest that you think quite carefully about not doing this. The first time I saw a bulleted list where the bullet was a pointing finger I though it was quite stylish. Now I have seen it hundreds of times and I find it annoying. This is an example of a 'visual cliché': an image that appeared charming and amusing when first used, but now only serves to annoy. I currently feel that one should only use images at all if they are part of the content of the presentation. The fact that software like PowerPoint allows you to produce slides whose background is a mountain range in no way suggests that you should do so. If you are using colour you have to be even more careful. Bear in mind that a fair proportion of people are colour-blind to a certain degree, so some colour combinations (e.g., red and green) should probably be avoided completely. A popular colour combination is yellow text on a dark blue background. In fact this is so popular that I now avoid it. Here are some other examples of visual cliché, particularly common in computer-assisted presentations:
- human figures pointing to things on slides;
- text dropping into place or sliding around;
- slides fading into one another;
- slide changes accompanied by a fanfare or other audio effect;
- animated bullet points.
Most academics, most scientists and many businesspeople are fussy about grammar and spelling. Some mistakes are worse than others, and each person has his or her own particular foibles. With me it's apostrophes: I get very grumpy when I see apostrophes used wrongly. Other people find other things objectionable. The only way to avoid annoying anybody is to make sure your grammar and spelling are faultless. I am surprised by how many students think this is not important. You should bear in mind that university lecturers read a great deal, and will be used to reading material where the writer has taken a lot of trouble over the grammar, spelling and presentation. To give a presentation where you have not taken trouble with these things is like turning up for a job interview wearing beach shorts and T-shirt (unless you're applying for the job of lifeguard, I suppose). It ought not to make any difference, but it does. If your grammar and spelling are not very good, all you have to do is find someone who is suitably expert and ask him or her to check your material. For a short presentation this will take about a minute, so no-one should object to doing this.
7 DeliveryNot everyone has an orator's speaking voice; however, everyone can be understood if he or she speaks at an even pace and faces the audience. The two most common delivery problems that I notice are speaking too quickly and facing away from the audience. Less intrusive but still annoying are fidgeting and repetitive gestures. I suppose that speaking too quickly is a sign of nervousness; perhaps it shows an unconscious desire to finish as quickly as possible. Facing away from the audience is just a sign of carelessness. When practising, you should ask your colleagues to shout at you if you do this. In a large lecture theatre hardly anyone has a loud enough voice to be heard while facing away from the audience. If your voice is so quiet that you can't be heard even while facing the right way, then you need some sort of amplification. You should check that this will be provided if you need it. Not everyone has my fog-horn voice, thankfully. Many people fidget during presentations. Partly it comes from not knowing what to do with your hands: people find it surprisingly uncomfortable to have their hands on public display and not to do anything with them. The same applies to a lesser extent to feet. I once attended a lecture where the speaker -- an eminent professor -- paced the entire width of the lecture theatre for the whole duration of his talk. It was particularly noticeable as the talk was being filmed, and the camera operator had to chase the speaker from side to side. I guess the speaker probably did not even know he was doing it (but the puffing cameraman should have given it away). The advice that most experts give is that you should stand with your feet about shoulder-width apart, and with your hands clasped behind your back. You will have to move, of course, to change slides and point at things, but other than that you should keep still. Personally I find this advice extremely difficult to follow. When I talk in social situations I am quite animated: I wave my arms and point at things and generally jump up and down. I find that I can't entirely suppress the urge to do this during presentations. However, if you have a tendency to fidget with your hands, you should certainly not put temptation in your way by, say, having a pen in your hand. Some universities make video recordings of student presentations so that people can see themselves as the audience sees them. Personally I think this is a good way to destroy any self-confidence that a nervous speaker has developed, so I don't do this. There is only one foolproof way to get these problems of delivery under control, and that is by practising over and over again, perhaps in front of critical but sympathetic colleagues. Many people find that they need written notes to help them remember what to say. When I first starting giving presentations I used notes. However, I soon found that I never looked at them, so I stopped using them. If you need the reassurance of having notes, then that's fine. The advice I received as a student, and that I still think is sound, is to make your notes on small cards rather than on paper. You can keep the cards in you pocket or otherwise out of sight, and only refer to them if you need to. You should never, ever read your notes out loud, if you are speaking your native language. Even if you have to read your notes and then speak afterwards, this is better than reading out loud. There are two reasons for this. First, if you are looking at notes you can't be looking at the listeners, so they won't be able to hear you as easily. Second, it will annoy the listeners, who will rightly think that if they wanted to read a presentation, they could read it themselves. However, people will make allowances for speakers who are clearly using what is a foreign language to them. Another piece of advice I received as a student, and that I still follow diligently, is to learn the first and last line of a talk. I would not try to learn by rote a complete talk, even a short one, but to learn the first and last line is a sound idea. At least your talk will start and finish smoothly, even if you make occasional mistakes in the middle.
8 QuestionsAt the end of a presentation you will normally be expected to take questions from the audience. If you have prepared properly and know the subject this will not present any problems for you. In a course presentation, the instructor may well ask questions that are very difficult to answer. The reason for doing this is to see how you handle them. The correct response to any question for which you don't know the answer is ''I'm sorry, I don't know''. You should never waffle or answer a different question. I can't stress this strongly enough. Time is short in a presentation session, and no-one wants to have it wasted by waffle. There is absolutely no shame in saying that you don't know the answer to a question. Similarly, if someone asks a questions that does not seem to be related to your presentation, it is perfectly acceptable to say ''I'm sorry, but I can't see how your question is concerned with this subject''. Of course you should not be rude to the audience, but at the same time you should not be expected to answer irrelevant questions. I find that I can often predict the sorts of questions people will ask about my own talks. I usually practice my answers to these questions in the same way that I practice the rest of the talk.