DESCRIPTION POINTS
P.E. ROWE
Description Points:
We need to communicate science using words, obviously. And words, as versatile as they are, have their limitations. Descriptive words like fast, heavy, strong, or large, are fuzzy, inaccurate, and not at all scientific.
Here’s what I mean.
Let’s say I think I’m a pretty fast runner for a writing instructor. On a good day, I probably am faster than the average teacher. But what does “fast” mean? A scientist (or even a track coach) would want to quantify that—just how fast am I and compared to whom, or what. Numbers are the right tool for the kind of specificity needed here, much better than the word “fast,” which doesn’t mean much unless we have a point of comparison. So let’s do a little comparing:
The teacher, with a top speed of 24.5 km/h might be correct in thinking he’s fast when he compares himself to other teachers. But the word fast no longer applies to him when making a comparison to say, a jackrabbit, who has a top speed of 64 kilometers an hour, or a cheetah, who’s even twice that fast. Which is to say nothing of other “fast” moving objects. Like a raptor—sorry, not that kind of raptor—, no, not even that kind of raptor—the Lockheed Martin F-22 Raptor, which, at altitude tops out at 2,414 km/h, about 100 times faster than that “fast” writing instructor, who at top speed looks like he’s standing still in the raptor’s rearview mirror. (Planes don’t have rearview mirrors, buddy—signed, the editor)
Teacher (top speed 24.5 km/h)—thinks he’s pretty fast
Jackrabbit (top speed 64 km/h)—not at all impressed
Cheetah (top speed 128 km/h)—considers both buffet items
Lockheed Martin F-22 Raptor (top speed 2414 km/h)—doesn’t bother racing animals
Numbers are great for recording things accurately and comparing, like that a jackrabbit is more than twice as fast as a human, and a cheetah about five times faster than a fast human.
But numbers also have a drawback when communicating research or results, especially to non-scientists. A lot of numbers are very difficult for people to grasp mentally, especially if they fall far outside the familiar human scale. So for example, that F-22 Raptor, if you were discussing jet propulsion and wanted to inform your audience how fast fighter jets currently fly, you can give them a number that’s accurate:
2,414 km/h
But that number out of context like this is going to be very difficult for your audience to understand. Given that people usually drive somewhere between 50 and 100 km/h in their cars, they’ll know that 2,400 km/h is fast by comparison. But that number won’t mean all that much to them beyond, really really fast.
This is a point in your paper or presentation where you need an effective strategy for describing difficult numbers in a way that makes sense to your audience. We have a couple techniques to help you communicate numbers like these in a way that helps your audience to understand them.
Let’s continue to use that example of the F-22 Raptor.
The first strategy to help you communicate how fast the F-22 flies is a comparative calculation. A comparative calculation uses that accurate number 2,414 km/h, and it gives the number a frame of reference so that the audience can process what that number means.
We can compare the F-22’s speed to other planes:
And Perhaps the best place to start would be with a plane that most of the audience would be familiar with, the most popular passenger airliner in the world, the Boeing 737. The F-22 is going to be much faster than a commercial plane, so it would also help to put the F-22 into better perspective by comparing it to the fastest plane ever, the X-15. Those sentences might go something like:
The F-22’s top speed of 2,414 km/h makes commercial airliners look sluggish by comparison, topping out at over two-and-a-half times the cruising speed of a Boeing 737. That blistering speed, though, seems modest when compared to the fastest manned plane ever, the North American X-15, which topped out at over 7,200 km/h—three times the speed of the F-22.
Now the audience has a better sense of what 2,414 km/h means with regards to being a “fast” plane. Much faster than anything they’ve ever flown in, but much slower than the fastest planes can go. Comparative calculations are very useful for building a frame of reference like this.
But that’s not all comparative calculations can do. Let’s see if we can do even better by putting these comparative calculations to work. Remember that the point of writing is to connect with the reader or audience. And one thing that people can conceptualize very well are images, so how can we find a way to turn that large abstract number into a much more concrete image in the reader’s mind? Instead of just comparing the speed of these planes to each other, we can use a benchmark—and preferably something that the reader can visualize or imagine.
In the case of the airplanes, I’m going to use a trip around the world—how fast would it take the aircraft at top speed to circle the equator completely. This isn’t that difficult a calculation if I can do it. You only need the circumference of the Earth in kilometers, and then you can simply divide that number, 40,075 km by the plane’s speed in km/h. Then we can compare the duration of the journey for the planes we want to compare.
