Effective oral presentations will contribute to the quality of the conference and the interest that your colleagues take in you and your work. Please read this advice and apply it sensibly.
You will have 30 minutes -- up to 25 minutes for your presentation followed by at least 5 minutes for questions from the audience. If you do not complete your talk within the allotted time, the session chair will have to cut you off to keep the conference on schedule, which is embarrassing for all concerned. There are two things you can do to avoid this embarrassment:
The amount of information you can convey in 25 minutes is limited. The amount of information a conference attendee will retain from an oral presentation after a long day of presentations is even less. If you try to deliver too much information, you will lose your audience and end up delivering no information at all.
The purpose of your talk is not to explain every detail of your work, but to make listeners aware of your work and to convey a few central points. Decide what those points will be and structure your talk around them. Begin your talk by enumerating these points. Avoid details that do not serve to reinforce these points.
The places for detailed explanations are in your written paper and in personal conversations. Feel free to refer your audience to the written paper for detailed treatment of topics that you touch on only briefly in your talk A successful talk will stimulate the interest of your listeners and encourage them to read the paper, to speak with you one-on-one at the conference, and contact you afterward.
Do not put more material on your viewgraph than the audience can easily absorb during the few seconds it will be displayed. Keep the viewgraph uncrowded, so that it is easy to read, even from the back of a large room. Use a large font -- at least 24pt -- and leave at least 3/16" (5mm) of space between lines. All the material in your viewgraphs should fit in a 7.5" x 9" (19cm x 23cm) rectangle. Landscape orientation is preferable to portrait orientation because it allows you to leave the bottom part of the screen unused. (The bottom part of the screen will be hidden from listeners in the back rows by the heads of listeners in the front rows).
Keep diagrams simple, so that they make their intended points clearly and forcefully. Your purpose is to communicate clearly, not to show off your prowess with PowerPoint. Do not clutter your diagram with distracting and nonfunctional "chart junk" such as decorative frames, three-dimensional effects and shadows, and pictures inside the bars of a bar graph or the slices of a pie chart. Design your diagrams as if you must pay for each drop of ink, and make sure that you can justify the "ink cost" for each element of your graphics. (In particular, tick marks and grids are often best omitted.) Remove details to which you will not refer in your talk. Use thick lines, since thin lines do not project well.
Avoid tables containing more than two or three rows and columns. Your audience cannot read all the entries of a large table in a few seconds. If you are interested in discussing only selected items from a table, highlight them in color or leave the other items empty. Better yet, use a graph to convey the underlying point you want to make about your data.
Use color where it is effective in clarifying your diagram. Do not use color simply for decoration, since this can distract or confuse the viewer. Avoid pale colors like pink and yellow, which are difficult to see on a projected viewgraph. If text appears over a colored background, make sure the foreground and background colors are contrasting. Maximal contrast is provided by black or blue against a white (i.e., clear) background. Red, brown, and orange contrast poorly with each other. Different shades of purple and blue contrast poorly with each other. Different shades of gray contrast poorly with each other.
Avoid switching typefaces, except for the occasional use of italics or boldface for emphasis, or to distinguish computer text from ordinary text. Avoid excessively ornate typefaces. Use mixed case rather than ALL CAPITALS. Leave the right margin of your viewgraphs ragged rather than justified; there is too little room on a line of a viewgraph to right-justify your text without introducing ugly expanses of whitespace between words.
Each viewgraph should have a title line summarizing the slide's message. Use bulleted text to emphasize the points that a viewgraph is designed to convey. A good rule of thumb is to limit a viewgraph to about six bullets. If you have more information than can fit comfortably on one slide, use more than one slide!
Reading code to your audience is not only boring, it is futile. It is very difficult to for a large audience to follow a presentation of program code. The typical listener cannot fully grasp the subtleties of an algorithm in the time you have to present it. To make matters worse, if your viewgraphs are set in a large enough font to be readable,very little program text will fit on one viewgraph. The only thing harder than trying to understand code as it is flashed on a screen is trying to understand code as it is flashed on a screen in sections.
In some cases, for example in a talk presenting a new programming idiom, the presentation of source code may be unavoidable. In such cases, try to keep your examples as short and simple as possible. Use ellipses and pseudocode to eliminate extraneous detail and emphasize the aspects of the program that you want your audience to remember.
Be enthusiastic. This is your chance to show off your work. You won't get the audience excited about what you have done if you don't appear excited about it yourself.
Speak slowly and distinctly. Use short clear sentences. Remember that some listeners will not be native English speakers.
Give your audience a chance to keep up with the material. Pause momentarily after you have presented a particularly complex, subtle, or important idea, so that your audience can digest it. It is also helpful to pause just after you have placed a viewgraph on the screen, so that the audience can read it (and so can you!). If you have succeeded in keeping your viewgraph simple, the audience will then be able to devote its attention to you.
Make sure that your talk is not too detailed to present in the allotted time at a comfortable pace. (See "Level of Detail" above.) Decide beforehand how many of your 25 minutes you expect to spend on each viewgraph. As you speak, stay aware of the passage of time, and have a plan in place so that, if you fall behind your schedule, you can recover by omitting less crucial material rather than by speaking more quickly or truncating your talk at an arbitrary point.
Maintain eye contact with your audience. Avoid reading from notes, and do not under any circumstances read word-for-word from a prepared text. Do not parrot aloud what the audience has already read on your viewgraphs. Use your viewgraphs as if they were notes, to remind you of what you plan to say, but elaborate on what is written.
Avoid standing between the projector and the screen, even if you are wearing a white shirt. If possible, stand alongside the screen (except while changing slides) to ensure that you are not blocking any part of the audience from the screen.
Avoid pacing and other nervous habits, but do not stand like a statue either. Use large gestures to emphasize your points, and move from one place to another occasionally to keep your audience alert and engaged.
Even an experienced speaker sometimes experiences a moment of nervousness or stage fright at the beginning of a talk, but this moment quickly passes as the speaker begins to present the substance of the talk. If you are an inexperienced speaker, you may find it helpful to memorize your introduction. This will give you a chance to overcome your initial nervousness and to become acclimated to your surroundings.
Your presentation will be effective only if you are confident. Rehearsing your talk several times is an excellent way to build your confidence. If you are an inexperienced speaker, you might want to rehearse your talk privately at first, but you should also rehearse it before a small group of friendly critics. The more familiar you are with your material, the easier it will be to keep your eyes on your audience rather than on your notes or viewgraphs.
No matter how experienced a speaker you are, we urge you to present the talk in your own organization before you come to SIGAda. This "dress rehearsal" is an excellent way to familiarize yourself with your material, discover what confuses the audience and what questions are likely to be asked, and to be sure that your talk fits in the allotted time. (A local dress rehearsal with a publicized date also ensures that you don't wait until the day before you get on the plane to start preparing your talk.)