The risks of dismissing minor usability issues

As a human factors psychologist, I am often asked to predict where users will (or have) run into problems with a product by evaluating its usability — the measure of its ease of use and ease of learning. 

At the conclusion of these evaluations, I categorize the issues I’ve found by severity on a scale ranging from minor to catastrophic issues. Catastrophic issues are those that must be addressed because they may cause the user to utterly fail at the task at hand, or, for medical and safety products, may even put the user or someone else in danger. Minor issues are those that should be fixed if time and resources are available.

But I’ve begun to question whether minor usability issues should be dismissed so readily. It’s true that a single seemingly trivial issue isn’t going to harm anyone, and a couple of them aren’t going to lead the user into utter failure. But minor usability issues are usually the product of careless design and a lack of attention to detail and, as a result, rarely occur alone. Cumulatively, these seemingly insignificant usability issues create significantly flawed products. 

Recently, as I was starting an interface evaluation, my initial reaction was, “wow, this is…not good.” But as I continued exploring the system, I realized that none of the problems I was seeing were ones that I would categorize as particularly severe. Rather the impression of a bad interface was being driven by a series of 9-10 badly designed microinteractions that I encountered repeatedly.

They were “minor” design issues, like having windows with X buttons that didn’t actually close the window, and others where there was no way to close the window except by clicking the X. The click targets were also small and non-responsive, so when I got no response, I was never sure whether the system was being slow, if I’d missed clicking the X, or if the X was simply not working. 

Other badly designed microinteractions included error messages that were inconsistent or presented in non-standard ways. There were checkboxes that appeared to be clickable, but weren’t, because they were being used an indications of states, rather than as controls. But like before, those checkboxes had small click targets, so when nothing happened, I wasn’t sure if I had missed the checkbox or couldn’t actually change it. 

Individually, none of these issues were terrible and all of them had a work around that only cost me a second or two. But this was a system that the users were expected to interact with for 8 hours every day, and these badly designed microinteractions existed in dozens of windows. So, the user would encounter them hundreds of times a day, adding hundreds of momentary hesitations, delays, and moments of confusion.

The point is that each and every usability problem, no matter how minor, detracts from your product. Each and every one can reduce users’ performance, delay their responses, and increase their cognitive workload. When those minor usability issues add up, in safety critical systems they can dangerously distract your user. For a surgeon in the midst of a procedure, those minor issues could mean the difference between a complete success and a less-than-optimal patient outcome. For an industrial hygienist monitoring gas levels, those minor issues could delay a reading by just a few seconds — but what if that reading indicates that immediate evacuation is needed? For someone controlling a vehicle, those minor issues might take the user’s eyes off of the path ahead for just a fraction of a second longer. But what if that fraction of a second were a critical one?

Even in non-safety systems, those minor problems amplify your user’s frustration and diminish his or her confidence in your product. Each of those so-called “minor” usability issues may just be a single straw — but we all know the proverb about the straw that broke the camel’s back. Are you willing to chance just how many minor issues your user will tolerate before they consider switching to your competitor?

At Daedalus, we consistently challenge our own standards to deliver the highest quality of work and put more good design into the world. Follow us on LinkedIn to read more of our insights and always feel free to shoot us a message if you want to talk about working with Daedalus to solve your complex problems. 

Twitter Digg Delicious Stumbleupon Technorati Facebook Email