Graphics images convey ideas. As such, they are not always precise. Hence, there
are many ways in which graphics can be misleading. In order to avoid sending
the wrong impression, you need to examine each image carefully. Look at both
the detail and the overall perception that is conveyed by the graph. Consider
an example where the CEO (Mr. Cruddock) has called a meeting to discuss sales
for the different divisions. Kwilla-June Holmes (the head of marketing) has
stated that the dog food division should be sold because its sales and profits
are lower than those of the other divisions. The head of the dog food division
(Vic) is also at the meeting.
| Ms. Holmes: |
And this graph shows the sales for the last three years for each of our product
divisions. Notice that the dog food division is lower than the others.
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| Cruddock: |
Uh, I can't quite read that graph. Are those bars made up of little dogs?
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| Ms. Holmes: |
(smiling) Yes they are. The new graphics package let me put different
objects in for the bars.
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| Cruddock: |
Hmmm. Well, is the top supposed to be at the dog's head or the tail? The tail
is quite a bit higher...
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| Ms. Holmes: |
Ah. I guess I don't know.
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| Vic: |
Our actual sales numbers are slightly below the other divisions, but only by 2
to 5 percent. Because she used those tall thin candles for the bars in the wax
division, it makes it look higher compared to the wider bar for the dog food
division.
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| Ms. Holmes: |
Sure, sure. I'm not criticizing your department. It just has less sales. Let's
look at the next graph. Here I created four graphs—one for each division. Each
graph has sales for the last five years. One bar for each year. Oh, notice that
all the bars in the dog food graph use the dog symbol and are the same width,
so it should be easier to compare.
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| Cruddock: |
 
Now, in this graph, it looks to me like the dog food division is doing better
than the others. See how the sales for all five years are near the top. But in
the cat food division they have two good years, but the other three are quite a
bit lower. Maybe we should solve the cat food problems first.
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| Ms. Holmes: |
But. Oh, I see the problem. Look at the numbers on the left. See, all of the
numbers for cat food are higher than those for dog food. These graphs are just
designed to show what happened in each division over five years. Let's just
look at one graph at a time. See how the dog food division hasn't changed much.
Its sales have stayed flat.
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| Vic: |
Wait a second, that's not right. Here, I've got the actual sales numbers. We've
increased sales by an average of 6 percent each of the last five years. Are you
sure you have the correct numbers in your graphs?
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| Ms. Holmes: |
Oh yes. I took them out of your report to Mr. Cruddock. See, check the numbers
on the Y-axis. |
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| Vic: |
Well, something's wrong with your graph.
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| Ms. Holmes: |
Maybe the next graph will make it clear. These four pie charts show the
breakdown of expenses for the last two years for the wax products division and
the dog food division. See this slice that I exploded out from the pie, it’s
personnel expense. Notice that it takes a much bigger share of the pie in the
dog food division, and it’s even larger in the next year. This increase in
labor cost is expensive because the division is not really growing.
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| Vic: |
Now wait a minute. I thought we settled that. We have been growing, that's why
we hired more people. And. . .
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| Cruddock: |
Hang on. Ms. Holmes, the slices for personnel in the dog food division appear
to be smaller than the slices in the wax products division. Why do you say that
the dog product's costs are higher?
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| Ms. Holmes: |
Oh that. I scaled the pie charts to match the overall sales of the division.
Notice that the entire pie for the wax products division is larger than for the
dog food. What I'm saying is you need to compare the percentage of the cost in
each case, not the actual size of the pie. I wanted to be sure to include all
of the information. It's a little confusing at first...
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| Vic: |
It's not confusing. It's just wrong. I don't know what you're trying to do, but
I'm not putting up with these inane graphs. Just look at the actual numbers.
Sure, we're not as large as the other divisions, but we're a whole lot more
stable. We've had five straight years of growth.
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| Cruddock: |
Ms. Holmes, thank you for the presentation, but I'm inclined to agree with Vic.
There might be some problems in the dog food division, but I don't really
understand your graphs. Next time, be a little more careful when you create
them.
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