Growing With the User

Employees start out green, but they don't stay that way, and that's one of the challenges with Point of Sale design: Often, what is optimal for new employees is not necessarily optimal for experienced employees. Some companies react to this realization by providing a second user interface—often called an "expert mode". However, this is rarely the best solution. Usually, it's better to create an interface that "unfolds" as the user bumps against the apparent limits an immediately-intuitive interface initially presents.

There are lots of ways to create a "growable" user interface, and the appropriate methods will be different for each client. However, one common strategy is to provide "shortcuts" that users can discover as they become more confident.

For instance, I recently designed a Point of Sale system which handled single-item purchases extremely intuitively. Through customer research at stores across the U.S., I knew that purchases of multiple identical items was rare. But I knew that at one point, more experienced employees would start looking for a way to do this more efficiently. So I built in a mechanism whereby experienced users could use the same interface, but in a way that would allow them to ring up multiple identical items more efficiently than inexperienced employees would do.

Consider not only offering alternative methods for accomplishing tasks, but also—and arguably more importantly—supporting user strategies that evolve as emploee tenure increases. For instance, I designed one client's interface such that commonly-paired buttons were side by side. This not only reduces hand movement (and thereby increases speed), but the buttons are placed in such a way so as to support a two-finger interaction as experience with the interface grows.

So far I've talked about extra things that help seasoned employees, but it's important to realize, too, that they also need less of some things. For instance, the text becomes less important over time while the placement of options becomes more important. To accomodate this shift, I typically design some labels (e.g., group headers) with a very low contrast so that they are visible to the new employee who is trying to understand the screen layout, but they fade into the background for tenured employees who don't need them any more.