Computer-Centered Computing: What Are “Human Factors” and Why Should We Care?

Abstract

Have you heard the old joke about the fellow who finds another chap searching for his lost car key under a single street lamp on a dark night? He offers to help and gets down on his hands and knees on one edge of the circle of light, but after a half an hour feels like he’s not having any luck.

“Are you sure you dropped it here?” he asks and the other fellow answers:

“Here? I didn’t drop it here. I dropped it about a hundred and thirty paces back, over on the other side of the street.”

Upset at having wasted his time, our hero asks why they’ve been searching on the wrong side of the road, and gets the following reply.

“Don’t be stupid! There’s no light over there. We’d never find my key in the dark.”

With that in mind, let’s consider a simple task, say, reading a sentence in a book.

I’m going to presume that you’ve just read that last sentence, and use it for my example. Now, if we were to try and express the task of reading that last sentence mathematically, there would be many factors involved. To reduce them to a useable example, and for the sake of expediency, we’ll ignore all of the factors that went into how you came to be reading that sentence, and just work from there.

Could you see the book and the words in it well enough to read them? Is there enough light, or maybe too much? Are the letters expressed clearly enough to be read, or do they seem blurry and out of focus? Should they be more sharply defined, or presented in greater contrast to their background? Maybe they should just be bigger? Maybe they should be written in a different language, presented in a different medium, or available at a different time or place.

Now where’s that warranty?