February 12, 2001

Engineers make obvious design mistakes

Summary: The engineers who build the products people use every day are not experts in user behaviour, and they frequently make mistakes that cause lost time and immeasurable frustration. Interaction designers could improve thousands upon thousands of products, leaving engineers to deal with the areas of their interest and experience.

Engineers are professionals. But they often overlook glaring usability concerns:

Each of those examples leads into a greater problem.

Why door handles matter

Donald Norman, a well-respected psychologist and human centered design advocate, introduced affordances to the world. Affordances are essentially the perceived properties of a thing, such as a door handle. Some door handles look like they should be pulled, because they have a shape which leads our brains to believe that is the best way to use the handle. Other handles look like they should be pushed, a feature often indicated by a bar spanning the width of the door.

For some reason, though, many doors have two push handles, or two pull handles. An ordinary, unsuspecting person, is likely to waste half a second or more, over and over again, pushing doors that should be pulled, and pulling doors that should be pushed. We've all done it, and we've all been frustrated by that simple, glaring oversight. If you think that such an incident will only happen once, think again: we push and pull doors all day, and pay less attention to our surroundings when doing so. In other words, we'll forget which doors should be pushed and pulled, and act based on the indications we're given, even if they are misleading. Additionally, most doors that suffer from this problem are in the commercial and industrial world, like in shopping malls or warehouses. We aren't likely to spend a great deal of time in any one of those buildings, and cannot be expected to remember the details of operating every door we encounter.

Programming mobile phones, and setting the clock on car radios

I had been using a Nokia phone for almost two years when I recently tried an Ericsson T-18z. I was used to the Nokia, and found its interface fairly easy to use, if a little difficult to learn. The Ericsson, however, was a totally different story. Aside from poor construction which made the phone's buttons distinctly un-buttonlike and difficult to press, Ericsson seems to have something against making a reasonably simple interface. The phone book requires the user to specify memory locations in which to store entries, and even worse, if you want to edit an entry, you must first memorize the memory location it's in. Computers are good at remembering arbitrary numbers; people aren't. Even after familiarizing myself with the phone book, retreiving numbers took at least seven or eight seconds, whereas with my Nokia it took about one or two seconds. It would have been faster to dial manually, but the keypad on the T-18z makes dialing nearly impossible.

I've been paying attention to clock-setting mechanisms in cars recently, and haven't found a single one that was obvious enough to require no explanation or clumsy trial and error. The most obvious system I found was one that had two tiny holes, labeled with a tiny H and a tiny M, respectively. Of course, one has to have a pen handy to set that clock. Others required bizarre combinations of buttons to be pressed at once, requring acrobatic hands. Setting radio stations or programming a sequence of CD tracks to play is no simpler, and that could cause driver distraction with disastrous results.

Getting lost in human environments

People don't pay much attention to signs, and they shouldn't have to. Signs slow people down, distracting them from their tasks at hand. Regardless, architects and consulting engineers design human environments that have horrid layouts and no clear indicators of where to go. Once the higher-ups realize there is a problem of some kind with the environment, signs are erected and people are expected to follow the signs. In parking lots, signs are almost always arbitrary: try to remember that the car is parked in A-53! Most people don't memorize locations by alphanumeric combinations; humans remember locations and routes by landmarks, or by forming a mental model of the space. Since that is the case, human environments should have properties that enable people to visualize their location, or remember obvious, unique landmarks.

The biggest problems still exist

The examples I have pointed out are very small and seemingly unimportant, yet they probably affect us all on a fairly regular basis. These obvious designs, these simple products, are noticeably flawed. If engineers can't get the simple products right, how can they get the complicated products right? They can't! Engineering the things we interact with on a daily basis is a full-time job that requires great skill and effort. Designing those products requires equal care from an interaction or interface design professional. Doors need the right handles, phones and car radios need to prevent distraction and frustration, and human environments need to let people know where they are.

Engineers have a tremendously important job, but since they have neither the time nor the expertise to worry about the dozens of human factors that are part of something as simple as a door handle, interaction designers need to help engineers develop effective products.

Adam Baker is a user experience designer who's worked at Google, Apple, BlackBerry, and Marketcircle, and mentored startups in Vancouver.