Advantages of overhead transparencies

• Transparencies are easy to make. Simply prepare your visual aid on paper and then copy it on a copier. But instead of copying onto blank paper, copy onto a transparency. This way you can make transparencies quickly, revise them quickly, and revise them often. You can also make them yourself, without waiting for a professional staff to produce them for you. This convenience often translates into whether people update their presentations or let them go stale.

• They're cheap. They cost only pennies a copy.

• They 're portable. For most presentations, you can easily fit your transparencies in your briefcase with room to spare. This is no small matter if you travel often. If you use cardboard frames around your transparencies, you increase the bulk somewhat, but they're still quite portable.

• They let you be flexible. You can rearrange your presentation on the fly—with the audience staring at you— to meet new needs. For example, occasionally someone needs an answer now for something you planned to cover later. No problem: just reach for the appropriate transparency and press ahead.

• You can write on them. Sometimes you don't want the audience to see a static visual aid (like a ready-made equation); instead, you want to create it, step by step, as the audience watches. With a transparency, you can do that easily. Some pens are designed for that purpose. An added advantage is that you can easily erase your writing later with a damp paper towel (if you're like me, however, you may walk around for a day or so with red or green or blue fingers).

• You can see what's next. Since most speakers handle their own transparencies, they can glance at the label on the next one and see what the next topic is. That's a really important advantage; otherwise, part of your mind is constantly trying to remember what's next. Sneak glances are no problem with overheads.

• They can look extremely professional. Color printers and copiers can enhance your message by drawing attention to key features and providing a visually interesting (yet still unobtrusive) background. You can also reproduce colorful photographs on a transparency and have good resolution.

• They can be informal if necessary. For an impromptu meeting with colleagues, you can simply hand print or hand draw your transparencies.

Disadvantages of using overhead transparencies

Alas, the world isn't perfect. Here are some of the disadvantages of using overhead transparencies:

• The projector may not be very good. Because overhead transparencies are the most popular visual aid, the equipment takes a beating. You'll often find projectors that don't focus well, have dim bulbs, or have no bulbs at all. That's why I carry my own projector for local presentations. When I travel, I insist in advance on a good projector. Then, when I arrive at the place for my presentation, I go immediately to the projector and try it out. If it's not good, I try to get another one.

• The bulb can burn out. Many of today's projectors have a spare bulb built in, but sometimes the spare is burned out, too. Presenters who have a bulb burn out switch to the spare and go on. They usually forget to tell the visual aids people that the overhead is now down to only one good bulb. If that one burns out, you're left with none.

Many speakers consider the overhead transparency their first choice of visual aid unless they have a good reason not to use it. But there are many good reasons to use other visual aids, either separately or in conjunction with overhead transparencies.

35-millimeter slides

Advantages of 35-millimeter slides

Thirty-five-millimeter slides can produce wonderfully professional presentations. You can show colorful word charts and colorful pictures, too. Audiences love real pictures— of things, people, even themselves. NASA has a speaker's bureau that uses slides, and you can imagine the beautiful photographs of space walks, the Earth, and rockets taking off.

If you want a thoroughly professional look with high resolution, slides are the way to go. They're also especially useful for standard presentations that many people give. For example, a woman I knew owned a business selling light fixtures. She made 35-millimeter slides of the fixtures her company had actually installed, and then she built her standard sales presentation around those slides. All her marketing reps used copies of that standard presentation.

Once slides are in the tray (right side up, facing the right direction) they stay right—and in the proper sequence. There is little fuss to handling them other than clicking a button to change to the next one.

Disadvantages of 35-millimeter slides

However, there are some disadvantages to using 35-millimeter slides. The most significant is that making them normally requires professional help. That means they're usually expensive and hard to revise.

They also usually take longer to make. And they're also virtually impossible to rearrange during a presentation.

Also important, the lights normally should be dimmer in the room for a slide show than for transparencies. That's restful for your audience. Very restful. And sometimes the lights in a room can be only all the way on or all the way off. With 35-millimeter slides, you'll have to turn the lights all the way off. As a result, the audience can't see you, and you can't see the audience. The effect is not good.

Finally, 35-millimeter slide projectors aren't nearly as common in conference rooms as overhead projectors, so you may have to carry your own. And if there is one there, it may have problems with jamming, focus, or burned out bulbs—and no spare projector.

Use 35-millimeter slides sparingly. They normally look great only when the lights are too dim for the audience and for you. This is a significant problem, possible, but hard, to overcome.

Computer presentations

Computer presentations are becoming ever more popular. Essentially, they project either onto a large monitor or through an overhead projector onto a screen. Many organizations have the equipment—even special rooms—for these presentations.

Advantages of computer presentations

If you're showing what a computer program can do, computer presentations are indispensable. And they're also useful replacements for overhead projectors, 35-millimeter slides, and even flip charts. They show color well, are very easy to create and modify, and can look highly professional. They are superb for animating your visual aids—for example, adding bullets step by step to a chart.

They can also be wonderful for doing "what if" presentations—perhaps using a graph, changing some values, and having a formula calculate a new result. For example, in a presentation on sales projections, you could change the projected sales figures in front of your audience's eyes, and everyone could then see the effect on your company's bottom line.

You can easily add graphics called "clip art"—pre-drawn figures you simply cut and paste into your computer presentation. Chapter 23, "Designing visual aids—further tips," has an example of clip art.

Computer presentations are very handy for standard (perhaps daily or weekly) presentations when data changes but format doesn't. The effort to prepare the computer presentation the first time is repaid ever after because updating the data—and, hence, the presentation—becomes simple.

Automated computer presentations are also handy at conventions when roving audiences stop in randomly. The computer show draws the crowd and keeps going longer than most human beings can. Also, for such shows, you can design participation: the user answers a question or pushes a button for some action.

Finally, you can have a wealth of backup material in your computer and call on it instantly if the need arises.


Use a computer presentation if you want that "professional look. " Or to show how a computer works or to put on a continuous display for an audience.

Disadvantages of computer presentations

Computer presentations depend on technology, so there's more to go wrong. And if something goes wrong with the equipment, you'll be pretty well stuck. Also, if you don't have good equipment, the projected image can be fuzzy or visible only to a narrow segment of the room. Even with good equipment, the room may be fairly dark.

The equipment—a computer (possibly portable) and a projection unit—is expensive, fragile, and awkward to carry (if it isn't set up permanently where you'll give your presentation). The equipment can also be time-consuming to set up and adjust.

The biggest disadvantage of computer presentations is the potential for real-time glitches not possible in other media. If you press the wrong key or enter the wrong data, the result may be unrecoverable. Back-up transparencies are often a good idea.

Nevertheless, computer presentations can be terrific. I believe the advantages often clearly outweigh the disadvantages. The key is to use the full power of your computer. Chapter 24 gives suggestions on how to design computer presentations.

Flip charts

Flip charts are very large tablets of paper on an easel.

Advantages of flip charts

Flip charts are useful for creating a visual aid "before your audience's very eyes." That is, you can start with a blank page, ask for the audience's ideas, and record those ideas on the flip chart. The effect is that you have your "sleeves rolled up" and are ready to get to work.

You can begin a presentation by making a list of what people in the audience want to talk about—they enjoy having you discuss and then check off their ideas. You can even have a volunteer come to the front of the room and record the audience's ideas.

Flip charts are also cheap, easy to make (even in advance), and easy to revise. You can tear off the pages and tape them around the room for later reference. Some people, particularly in informal presentations, put their blueprint on a flip chart and leave it in view. Then they use overhead transparencies or some other means for the main part of their presentation. When they're ready to move to another section of their presentation, they simply walk over to the flip chart, point out the next item on the blueprint, and move on.

Flip charts are also easy ways to use color—simply have a handful of colorful pens and you can put your artistry to work. Some speakers like to make all headings one color and all text or bullets another.

Tip _____________________________________________________

Use a flip chart for a "sleeves up " approach when you have a small audience and want to record the audience's ideas during your presentation. Or use it if you want to keep the pages on display around the room.

Disadvantages of flip charts

The main disadvantage is that flip charts won't work for large audiences—those sitting in the back of the room may not be able to see them. If your audience is small, you have no problem. They're also cumbersome to carry around, and they're hard to save or reuse. The pages sometimes crinkle—noisily—when you fold them back. And they require an easel (not always available), which makes a nice object for people to back into or trip over.

Flip charts also usually look homemade and depend on relatively neat handwriting (legible, at least).

If you're writing on a flip chart during your presentation, you may have trouble writing neatly and talking at the same time. And even if you're a good speller, your hurry to put words on the page in front of your audience may cause a handwritten "typo." (Or "thinko," as I've heard them called.) Then that misspelled word will stay in front of your audience's eyes, constantly distracting them. Also, the writing from colored pens can bleed through to several sheets beneath.


When using a flip chart, leave one or two blank pages after every page you write on. That will avoid showing the bleed-through that occurs. You may also want to put tabs on the pages you plan to use. That way you won't have to turn a number of blank pages to get to the one you want.

Blackboards arid whiteboards

Blackboards and whiteboards have essentially the same advantages and disadvantages as flip charts (except you can't pack a blackboard and take it with you, and you can't page back and forth). I especially like whiteboards because they lighten the room and show color well.

The biggest caution for whiteboards is the pen: some pens are intended for whiteboards and erase easily; some don't erase—ever—and give memorable indigestion to visual aids people. In fact, visual aids people try not to allow permanent marking pens in the same room with a whiteboard.

If you're using a whiteboard, check the pens in advance. Otherwise, you may be embarrassed when you try to erase the board and find—behold!—the words just stay there, giving a whole new meaning to "my words will live forever." You'll want to slink quietly off.

Objects and models

Sometimes there's simply no replacement for an object itself. If it's small (like a new kind of light bulb), there's no reason to have pictures or diagrams of it. Just show the light bulb.

If it's large, like a new building—or tiny, like an atom—a model can be the highlight of your presentation: professional looking and interesting.

Don't pass an object around the audience. You '11 be creating your own greatest distraction: people looking at the object simply won't be paying attention to you. Just hold the object up or walk quickly around the room with it. If it's not fragile or expensive, consider leaving it on display for a few minutes after your presentation.

Imaginary visual aids

Yes, some of the most creative visual aids I've seen in presentations haven't even existed. Here are some examples of imaginary visual aids:

• One person was showing the distance someone could broad jump. So she made the stage an imaginary place for the event, started at one edge, and walked the distance for the high school record. She talked about that awhile, then moved a little farther to show the collegiate record. And so on.

• Another person turned the stage into a boat. He showed us where starboard was, the stern, and so on. He used the stage as his reference throughout his presentation.

• Another made the stage an airport, showing which directions the planes would take off and land, where the gates were, and where the control tower was. She then used this to illustrate the various traffic patterns the planes would fly, depending on the direction the wind was blowing.

Such creativity isn't too informal: these speakers were in relatively formal situations, and their creativity added liveliness and interest.

Handouts as visual aids

An all too common visual aid is the handout. Inexperienced speakers often pass one out even when there's no immediate need. The result is a major distraction. Simply look around the room, and you'll often see people leafing through the handout rather than looking at the speaker.

In fact, Jim Casimir, a top executive, says, "A good rule is never use a handout during your presentation."

If you must use a handout during your presentation, I suggest these steps:

• Pass out the handout yourself, counting out the right number for each row. That's faster than dropping off a bunch at one side of the room and waiting for copies to get to everyone. In a large room or auditorium, ask several members of the audience to help you. You can increase their efficiency by giving them specific instructions: "Please take the left side and count out the correct number for each row. Thanks."

• Go through the handout as a group, pointing out what, specifically, the audience needs to look at. That way, everyone's attention will be focused.

• When you're through, ask members to set the handout aside. I say something like this: "Okay, we're through with the handout, so if you'll set it aside, we'll move on." Audiences rarely seem to feel dictated to. They simply set the handout aside and look up.

Some organizations are used to passing out a paper copy of their visual aids to the audience. If possible, do that at the end of the presentation. That way the audience isn't distracted.

We've covered many kinds of visual aids, each with advantages and disadvantages. The next two chapters offer suggestions on how to design them.

Designing visual aids

Bottom line

Simply having visual aids is a good start, but having well-designed visual aids can make all the difference.

This chapter deals with the fine points of designing visual aids that look good and help you and your audience, I'll concentrate on the overhead transparency, because it's the most common visual aid and because the fundamentals for it apply to other visual aids, too.

And, as you'll see when you get to Chapter 24, the fundamentals here apply fully to designing computer presentations, too.

Some organizations have standard formats for their visual aids. But lots of organizations don't. In fact, you may be your own typist, graphic artist, typographer, and photocopier. Many of us are. If so, this chapter will help you design your own visual aids well. If others do your typing and designing, this will help you tell them what you want.

Margaret Raab, in The Presentation Design Book, says that "good graphic design is invisible." So true. For most occasions, we don't want the audience to gasp with pleasure at eye-catching visual aids. Instead, we want them to concentrate on the content—to pay attention to what we're saying rather than to how we're saying it.

Keith Thompson, in PC Publishing and Presentations, expresses a similar idea: "Your slides should reinforce your message, not overshadow it. To put it another way: the speaker needs to remain the center of interest, not the slides."

Of course, there are exceptions. It's fine to show off a little. But you'll usually want your visual aids to have straightforward efficiency.

Here are suggestions for designing efficient visual aids:

• Use a title transparency.

• Put the words near the top of each transparency.

• Don't put several ideas on the same transparency.

• Use a single orientation: all landscape or all portrait.

• Usually avoid borders.

• Place logos effectively.

• Consider using frames to hold your transparencies.

• Label your transparencies.

Let's look at each of these more closely.

Use a title transparency

Your first transparency should have at least the title of your presentation and your name on it.


If the title of your presentation has unfamiliar terms in it, you may want to leave the title transparency on while you define those terms. I've seen people spend two or three useful minutes on the title transparency before moving to the next one.

Some speakers decide to replace their name on their title transparency with the name of the person or organization they're speaking to.

That's normally not a good idea: members of the audience know who they are, but they don't necessarily know who you are. They'll be happy to see your name so they'll know how to refer to you during the presentation.

By the way, I suggest you use the name you want people to call you: "Ed Bailey" instead of "Edward Bailey" or "Professor Joan Hiller" instead of "Professor J. Hiller."


You might want to have a test transparency—all mine says is "test transparency test transparency test transparency. ..." That way, when you're testing the overhead projector and some members of the audience are in the room, they won't see one of your actual transparencies.

Be sure to use typical type sizes on your test transparency, including your smallest type size.

Put the words near the top

Most of us like the symmetrical appearance when we center things, so naturally we want to center the words (or diagrams, or pictures) on our transparencies or other visual aids.

Centering often looks nice on an unprojected transparency and on the paper copy we use to run a transparency. But keep in mind that audiences can't always see all the screen—those in the back may be able to see only the top of it.

So I always work from the top of my transparency, because the top of the screen is visible to everybody in the room. That is, I center my text from left to right but not from top to bottom.

In other words, not like this:

C\ ^ Tasks of a Desk Editor pagefitting stylizing sourcing

I think of the top of the screen as "golden" space I want to make the best use of. (Experience has been my teacher on this!)

So here's the way I would actually design that transparency:


Tasks of a Desk Editor

• pagefitting

Putting the words on the top doesn't make the transparency appear distorted or off-balance, does it?

You may think you can just push the transparency up on the projector during your presentation. But that's one more thing to think about and can seem awkward. Instead, just keep your words and images high.

Don't use too many words for each idea

Perhaps the most common mistake is putting too much material on visual aids.

The temptation is to put everything there: that way, you won't forget anything.

But if you put everything you have to say on your transparency, you'll end up reading it aloud, turning to your next one, reading that, and so forth—leaving nothing else for you to say. Audiences don't appreciate hearing speakers read most of their presentation.

Here is a transparency with wall-to-wall words:

What Headhunters Do

The first task headhunters do is find openings in other companies. These openings should normally be for relatively senior people who have special skills or academic qualifications. The second task is to find prospective employees to fill those job openings. In addition to good paper qualifications, they must be effective managers; otherwise, companies won't use our headhunters.

Finally, headhunters must match employees and openings to make sure there's a good fit.

Instead, choose a few key words to serve as reminders. As I mentioned earlier, these reminders are like the headings and sub-headings you might use if you'd written your entire presentation.

Here's a revision, this time with only brief verb phrases as reminders:

n ^ What Headhunters Do

• find job openings

• find prospective employees

• match employees and openings

You've now left something to say, so you won't just be reading aloud. This isn't a small point.

Most presentations by inexperienced speakers have far too many words on the transparencies. That virtually guarantees problems: the audience won't want to read the transparencies because they look cluttered. And if the speaker does nothing but read transparencies, the audience gets upset.

That's not to say that transparencies must have only simple phrases on them. Short sentences are okay, especially for questions and brief quotations.

Just work for less rather than more—let phrases be the norm and full sentences be the exception.

Some organizations encourage speakers to leave a paper copy of their visual aids with the audience. As a result, speakers tend to make the visual aids self-explanatory so the paper copies will stand alone. The actual visual aids then become much too wordy. Instead, make your visual aids the best you can for your presentation, then annotate the paper copies to help them stand alone.

Don't put several ideas on the same transparency

Another common mistake is putting too many ideas on the same transparency.

This happens often with beginning speakers. But, as with other things, less is often more. Here's a busy transparency from a presentation on expert systems:

Expert Systems

Mechanical expert system

Symptoms: the engine won't start, the lights are off, the radio won't play

Solution: recharge or replace the battery

Medical expert system

Symptoms: runny nose, sore throat, coughing Solution: the patient has a cold

See how cluttered that looks?

Just because material can fit on a transparency doesn't mean it should be there. A simple transparency focuses the audience's attention on those few simple points. A cluttered transparency, on the other hand, may distract so much that the audience doesn't focus anywhere at all.

So let's take each section of the cluttered transparency and put it on its own transparency. Here's what the same words on two transparencies could look like:

s Mechanical expert system



• recharge battery

Medical expert system



By using two transparencies, you can also improve the layout—adding white space and bullets.

Use upper and lower case

Before computers, which can easily vary type size, speakers often used all upper case (capital letters) on transparencies. That was the only way a typewriter could make words large enough. Today, however, researchers believe that a page entirely in upper case type is hard to read:










Instead of using all upper case to get larger letters, just use mainly lower case in a larger type size:

• Capacity to repay

• Capital to cushion against losses

• Collateral

• Condition of the economy

Looks can be deceiving. What looks plenty large on the transparency you're holding in your hand can look awfully small once you project it on the screen. Too often speakers wait until the actual presentation before testing their transparencies—then look with shock at the small letters.

Inevitably, they mutter something like, "I hope you all can read this." That doesn't make for a strong start, and it throws the speaker off guard, too.

There isn't any right type size to use because:

• projectors have different focal lengths

• the size of the projection on the screen depends on how far the projector is from it

• in a large room people may be farther from the screen than in a small room

Use large letters

Even though these variables exist, I rarely use a type size smaller than 20 points. I normally use 28 points or larger. In case you're not familiar with point sizes, here are samples:

This is 20-point type.

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  • grace
    What is an overhead transparency its benefits and demerits?
    9 years ago
  • Idris
    What is the advantage and disadvantage of overhead transparencies?
    3 years ago
  • curtis
    What is advantage and disadvantage of overheaded transparencies?
    3 years ago
  • cherubino
    How many woreds can i put on an overhead transparency?
    2 years ago
  • asmara
    What are the advantages and disadvantages of transperencies?
    2 years ago
  • garfield
    What is the advantages of using transparencies?
    2 years ago
  • Helj
    What is over head transparency as a visual aids during presentation?
    2 years ago
  • Simon
    What is the important of transparencies on layout features?
    1 year ago
  • gabriele
    What is overhead transparences and examples?
    1 year ago
  • america
    Are transparencies useful visual aids?
    4 months ago
    What is the advantage and disadvantage of slides and transparencies?
    3 months ago

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