The flaw of averages

In order to empower everyone in our audience, not just those who happen to be without disabilities, one has to purposefully put a few concepts into practice. Before we can even consider, or even design our experience for any given set of abilities or disabilities, we must recognize that people, whoever they are, do learn and process information in different ways.

We’ve already explained why a one-size-fits-all approach to delivering your presentation will rarely please everyone. It almost never does, in fact. What may work well with one group will fall completely flat with another. That funny bit you tried last time may not work at all in another environment.

How successful you are with delivering a message depends on who you talk to, how you bring your ideas forward, the mood these people happen to be in, and the culture they belong to. As someone who looks to deliver a message, what will your strategy be to get, not only through their heads but also through their hearts?

The answer might lie in one of my favorite stories, which involves the design flaws of the 1926 United States fighter plane cockpits.

Crashing planes and fitting in

Picture yourself in the late 1940s. The Great War has been over for a few years, and technology evolved quite a bit.

So much so that now, the United States Air Force has a serious problem: pilots can no longer maintain control of their planes. The issue became so critical that on a particularly grim day, a total of 17 pilots crashed their planes! Follow-up research showed that pilots weren’t to blame; procedures were followed, and protocols were respected. Something else was causing all these planes to crash and these lives to be lost.

Everyone was wondering: if the pilots aren’t responsible for the crashes, then who is? What is the problem? Why has it become so hard for these men to remain in control of their aircraft?

How army researchers eventually made sense of the situation might surprise you.

You see, back in 1926, when the U.S. military was designing its first-ever cockpit, engineers had standardized dimensions based on data gathered from measuring hundreds of pilots. For over 20 years, the size and shape of the seat, the distance between the pedals and the stick, the wind shield’s height, and even the shape of the pilots’ helmets were all built according to the average dimensions of the average 1926 pilot.

It appeared as though the cockpits were no longer adapted to the pilots’ changing bodies. Could it be that this new generation of pilots had gotten bigger over the years?

By 1950, a desperate U.S. Air Force authorized a new study, this time to capture the average measurements of over 4000 active pilots on 140 physical dimensions, ranging from aspects like body weight and height to other things like the distance between their thumb and index, or their eyes and ears. Everybody believed that redesigning the cockpits based on the new average measurements made sense, and would fix the problem once and for all.

But a young Lieutenant by the name of Gilbert S. Daniels felt otherwise. Little did he know, Daniels was about to make a discovery that would change the world of design forever.

Using the data gathered through this extensive study, Daniels calculated the average of the 10 physical dimensions believed to be most relevant for cockpit design. Those included height, chest circumference and sleeve length. They formed the dimensions of the “average pilot.” The perfect measurements according to which, the U.S. Army would be able to create a new, updated cockpit.

What Daniels discovered stunned everyone, including himself. Of all those 4063 pilots, not a single one scored within 15% of the expected average on all 10 dimensions. Some came very close, but there was always something. Their arms were shorter. Their chests were narrower. Their legs, longer. Their heads bigger. There was always something that wasn’t “quite right”.

This very important discovery led Daniels to understand that if you design a cockpit to fit the measurements of the average pilot, then what you’ll design is a cockpit that will fit no one. The solution, therefore, was not to build a cockpit based on average measurements but to build one that could be adjusted to the pilot. An incredible, radically disruptive discovery.

And this makes sense… If you’ve ever rented a car or shared one with someone that was of a different build than you, then you know. You know how important it is to adjust the mirrors, the seat, and even the steering wheel before you hit the gas. You want to make a few adjustments, so you feel everything is adapted to you and your needs.

From the cockpit to the stage

Likewise, if you spend any amount of time thinking about inclusion challenges in public speaking, then Daniels’ discovery from over 70 years ago should resonate with you, too! Slides and content built to please the average audience member rarely account for the particular needs of those who have disabilities.

Content that heavily depends on visuals is likely to be lost to audience members with visual impairments. Information conveyed through colour alone is likely to be unusable for those who are colourblind or have colour perception deficiencies. Videos that are not captioned are likely to be incomprehensible to people who cannot hear well. Word-heavy slides are likely to be unreadable for people who have dyslexia or poor reading skills.

Content delivery prepared for the average audience member will only work as long as your audience fits within all predefined parameters of what we would consider being the average audience member. As soon as part of your audience has any kind of challenges with the way you created or delivered part of your content, then they’re out of luck. Off to Fadeout Town they go.

What Daniels’ findings have taught us is that the vast majority of people out there never perfectly fit the mold of the “average user”. The law of average is flawed. But yet, it prevails. And we, as professional communicators, keep making the most uninformed decisions, oblivious to how flawed it is.

On the surface, designing content to appeal to what we believe to be the majority of people seems like a reasonable idea. Until we start paying attention to the minority, and how many people actually belong in that minority.

As the next few posts will discuss, the demographic of people with disabilities and the elderly combined constitute the largest minority group out there. A minority group that any of us can join, at any given time, or will join if we’re lucky enough to live a long life.

Let that sink in for a moment. What are you doing today, as a professional speaker monetizing the spoken word, to cater to the needs of audience members who, like these thousands of pilots in the 1950s, didn’t quite fit the perceived mold of the average pilot?