What is Human-centered Design?

Human-centered design is everywhere.

Look, and feel the chair that you are sitting in right now. If you are sitting in a modern office chair it probably has adjustable arms, the height of the chair can be adjusted to match your height. Most likely the bottom of the chair has special contours to better match the shape of your butt. This is Human-centered design. The developers of the chair knew that humans would be sitting in the chair and they made special design considerations to make the chair better match their human user.

You are probably already familiar with the term “ergonomics”. The American Heritage® Dictionary says that:

Ergonomics is the applied science of equipment design, as for the workplace, intended to maximize productivity by reducing operator fatigue and discomfort. Also called biotechnology, human engineering, human factors engineering.

Do you remember that last time that you rented a car? How long did it take for you to figure out how to start the car? How long did it take for you to put it into gear and drive off? How long did it take for you to find the switch to turn on the headlights? What about unlocking the gas cap? Each of these are additional examples of hardware ergonomics and human factors that I’d imagine that most of us are quite familiar with.

It probably did not take too long for you to figure out how the start the car, you just put the key into the ignition and turn it clockwise until the engine starts. Putting it into gear and driving off seems pretty easy for a car with automatic transmission (as are most rental cars) you just move the PRNDL to the gear that you want. What about the lights? Maybe this took a little bit of extra effort. Was it the same for the gas cap? Why?

Usability and Human-centered design are based upon the concept of Human factors engineering. Engineering products to match the various factors associated with being human. The most obvious Human factors are those that are physical in nature.

That is why the seat you are sitting on is specially contoured to match your behind. That is also why the ignition and the gear shifter for your American driven car are on the right side of the steering wheel—because about 85 percent of the population is right handed.

What about human factors engineering for the non-physical? How did you know to turn the ignition key clockwise to start the car? This is because you may have had some experience with cars before and have created a “mental model” of how to start a car in your head. You then can transfer this mental model to the specific car that you have just rented. You can easily start the car. What about the lights or the gas cap lock? Some cars have the headlamp switch combined with the turn signal switch, while others have the switch mounted on the dashboard. Your mental model might clash with that of the rental car. The same is likely true for the locking gas cap.

So what does all of this talk about rental cars have to do with a software project? Well, nothing really, but it is easier to explain hardware human factors than it is to explain software human factors. So now that we have the common understanding (your new “mental model”) of human factors, we can explain with some ease about software human factors, usability and human-centered Design.

Using an EHR or some other software application initially is much like renting or buying a new car. You already have some notions as to what type of interfaces to expect and what actions you can perform. You already have a mental model of how to use a website or a “Windows™” application, for example. That mental model is what guides your behavior when using most any computer application. Instead of designing a chair to better match your physical self, UX professionals will use software human factors to help developers design software to match your thoughts and expectations.

If users can come to your website, EHR, or use your applications with considerable ease—when compared to, say your competition—they will likely make less errors, be quicker, and be happier. Hopefully making you and your company much more money.

Wait... there is more:
Don't design just for the novice user--Make sure you Aim for the middle!