|
|
|
|
|
|
|
|
||||
|
|
|
|
|
|
|
|
Form
and Content:
No matter how brilliant your ideas, your
graphics can clarify or obfuscate your message equally well. Graphics can
help you communicate better, and visuals will keep your audience with you. On
the other hand, too many slides, the wrong illustration (a complex table that
could be summarized by a simple chart), poor color choices, or gratuitous
decoration may prevent attendees from understanding your message. Remember,
most people retain more of what they see than what they hear.
|
|
Understanding Your
Medium:
|
|
|
|
|
|
||
|
|
2 |
|
||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Overhead films or viewgraphs: Again, the films are projected onto a screen. But the projected image tends to be weaker, making it preferable to use light backgrounds and dark text and graphics. Again, use a horizontal format. Although most film is A4 or 8.5 x 11 inches, use the center 2/3 of the sheet when oriented vertically. Don't crowd the top and bottom of the sheet because very often, the projector or screen is poorly setup and the top or bottom of the image will be cut off. Also, if the screen is not exactly perpendicular to the projector lens, the top or bottom of the image will be out of focus. |
|
Computer presentations: These too are projected images reflected from a screen, but you create them on a computer display that is an emissive device. You can be easily fooled into choosing contrasts and colors that look good on the computer screen but project poorly in a lecture hall. Follow the same guidelines for slides when choosing color and background. Many slide-making programs force you to use a horizontal format; this constraint is not a bad thing. Projection may be done via a liquid crystal display (LCD) on an overhead projector or via a color projector. N.B.: In a large room, the projected image may be dim, so provide good contrast. |
|
|
|
|
|
||
|
|
3 |
|
||
|
|
|
|
|
|
|
|
||||
|
|
|
Elements of Style |
|
|
|
|
Text vs. graphics: You have a choice of using letters and numbers or pictures to convey a point. Even a well-designed table will contain too many characters, making it confusing, whereas the same information can be easily summarized in a good plot or chart. Organization: Where you decide to put the information on the page affects understanding. People read from the top down, and they will read the most obvious part of a graphic first. Labels on graphics should be near the parameter described; they should be legible but not overwhelm the data. Use space to group related parts. |
|
How many: An illustration every one to three minutes is good pacing for most talks. Too many illustrations will tend to stupefy the listener. How much: Too much information per illustration is
difficult to comprehend. Stick to the salient points. Use different slides
for unrelated ideas. Three to seven lines of text per slide are enough.
(Also, see typography below.) In general, a
single illustration should contain a single graphic, and complex graphics
should be avoided. |
|
|
|
|
|
||
|
|
4 |
|
||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Where to put it: The almost 2:3 proportion of the projected area of 35-mm slides or horizontal computer presentations allows sufficient space for a title (if needed) and several more lines of text or a graphic below. For legibility, titles can be centered, but following lines of text are easier to read if left-justified. (Multiple lines of centered text are more difficult to read because your eye has to search for a new starting point for each line.) Bullets can provide an additional left anchor to organize related text. |
|
|
|
|
|
|
|
|
|||
|
|
5 |
|
|||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
The size of characters clearly affects legibility. The chart on the previous page gives the body sizes of type (in points*) using Helvetica as an example. For slides and overheads, text should be in at least 18 to 24 point type; use size to establish a hierarchy for titles, subheadings, and text. For titles, 42 to 44 point type works well. If you can't read the text six feet from your computer screen, it's too small. (Also, if you can't read the text on the actual 35mm slide without a magnifying glass, the type is too small.) The distance between letters can be controlled in good page layout programs and even some word processors like Word. In drawing programs, the control is letter spacing, call kerning, is variable. (The default kerning in Canvas for Windows 95 is abominable.) In general, the default spacing for a given typeface will work, but when working with larger sizes of letters, you may need to adjust the spacing. |
|
White space between
letters in a word should be even to your eye. Spacing in some letters can
cause problems: The space between mostly straight-sided letters is generally tight, but the spacing between letters such as O and its neighbors may need adjustment as indicated. The default kerning in this example definitely needed some adjustment by eye. Spacing between lines is also generally controlled by the program that you're using. Use space as a graphical element to group related items are together. They should be together, but not cramped. On the other hand, avoid too much empty space since it may confuse the relationships among the parts. |
|
|
|
|
|
||
|
|
7 |
|
||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Computer-only presentations use a WYSIWYG (what-you-see-is -what-you-get) medium. That is, all images are formed by the pixels on your monitor which limits the final resolution to 72 dots per inch. On the other hand, sending your presentation to a laser printer with a resolution of 600 dpi (or a high resolution printer at 2,000 dpi) gives you smoothly rendered characters and graphics. Although you're stuck with a low-resolution display, there are some ways to improve the on-screen appearance of text. First, you can use fonts that are designed for a computer display rather than for printing. |
|
Several of the type
faces mentioned above-Times Roman and Helvetica, for example-are venerable
old faces designed to be printed by type on paper. (For high resolution, cast
metal type is about as good as you can get. Is this, perhaps, the "Lead
Standard" for text legibility?) Fortunately, there are typefaces
designed to be legible on your computer screen. Several are available for
free from Microsoft, or for
a modest price from Adobe.
I've come to like |
|
|
|
|
|
||
|
|
8 |
|
||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Second, you can use "anti-aliasing" to lessen the on-screen jaggies that result from trying to map curved characters to discrete pixels. Anti-aliasing is a method of smoothing a character's jagged edges by slightly blending the character's pixels into the background color. Microsoft provides a Font Smoother for free, and AdobeType Manager 4.0 includes the Smooth Font Edges on-screen option. Smoothing should improve the legibility of most of the large characters used in computer-generated presentations. |
|
*Some measurement esoterica. Type is measured in
points. "How big is a point?" you may ask. Well, there are 12
points per pica. "Right. Ask a silly question . . . “O.K., there
are 6 picas per inch, so a point is 1/72 or, 0.0138, inch. Although
other countries measure type in points (but 12 points per Didot are bigger at
0.0148 inches per point), US/British units are common. Metric type
measurements, however, are increasingly common. For example, in the |
|
|
|
|
|
||
|
|
9 |
|
||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Use different colors to separate idea, but use similar colors to carry an idea across several slides. Do not use more than five colors per slide. And watch the color combinations you select. In particular, avoid red/green color combinations. About ten percent of your audience cannot distinguish between these colors; besides, the combination should only be used in Christmas decorations. A large area of color looks more saturated than a small area of the same color so a subdued tone for large areas will not dominate and detract from your message. |
|
|
|
|
|
|
|
|
|||
|
|
11 |
|
|||
|
|
|
|
|
|
|
|
||||
|
|
|
|
|
|
|
|
Useful
Graphics vs. Chartjunk
|
|
Decide just what a plot
of data should tell the viewer. Look at the elements that go into a
graph. Do the scale marks inform? Do you need those reference grids, lines,
and boxes? Probably not. Using heavier lines and denser colors will help your
data stand out from lighter reference graphics. Look at the ways to
distinguish areas from one other. Angular cross-hatching can be very
confusing, and fill patterns may shimmer or produce moiré patterns. Data
labels should be unobtrusive and not crowd the data themselves.
|
|
|
|
|
|
||
|
|
12 |
|
||
|
|
|
|
|
|
|
|
||||
|
|
|
|
|
|
|
|
Before Making the Final Product Remember to proofread. There's nothing like a nicely crafted slide with spelling or punctuation errors projected in two foot-high letters to make you look careless. Use a spellchecker, but watch out for mistakes that spellcheckers miss. It's best to have at least one other person read the text. Keep in mind that what you see on your computer screen may look different when you go to another display medium. Printers, slide makers, and film recorders may produce some bad surprises. Your slide production lab may have specific advice for their equipment. |
|
Finally, getting to a good presentation is like getting to Carnegie Hall: Practice! Practice! Practice! You may have the most brilliant slides in the world, but if you're uncomfortable delivering your presentation, you are doomed. |
|
|
|
|
|
||
|
|
13 |
|
||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Tufte, E. R.:
The Visual Display of Quantitative Information. Graphics Press, Cleveland, W. S.: The Elements of
Graphing Data. Tukey, J. W.: Exploratory Data Analysis.
Addison-Wesley, |
|
Reynolds, L. and D. Simmonds: Presentation of Data in Science. Martinus Nijhoff, The Hauge, 1982. [How to produce good illustrations. Concise, clear, attractive, and extremely useful. A joy to read.] White, J.: Graphic Design for the
Electronic Age. Watson/Guptill, Adobe Systems, Inc. Using Type. Jan. 2002. http://www.adobe.com/type/ [Type on your computer screen. Lots of interesting and useful stuff.] Microsoft Corporation. Microsoft typography. Jan.
2002. http://www.microsoft.com/typography [Type and the web browser. Windows and Macs
included.] |
|
|
|
|
|
||
|
|
14 |
|
||
|
|
|
|
|
|
|
|
||||
|
|
|
|
|
|
|
|
Acknowledgements |
|
In memory of my friend,
Cary Lu, who enjoyed the esoteric, and did many wonderful things with
Macintosh computers and film. |
|
|
|
|
|
||
|
|
15 |
|
||