ThinkFlood Blog

If my posts of the last couple of days seem rather rambling, I am trying to draw some conclusions. In particular, I would like to develop a framework for usability design – a number of principles that are fundamental to the usability puzzle that can help to guide design decisions. I propose that the first of these principles (i.e., the most fundamental) is minimalism.

Why minimalism? Once again, I turn to the issue of subjectivity. Different people perceive the same design in different ways; what makes sense to one may be incomprehensible to another. It follows that the more facets there are to a design, the more chance that some facet will be confusing to some people. Stated another way, each aspect of the design confuses some portion of the population. By reducing the number of facets, we reduce the total potential for confusion. I began to allude to this point yesterday when I identified the business tendency to add features as a practice that can hinder usable design.

Before we go crazy over minimalism, however, we need to differentiate this approach from nihilism. I’m not talking about political movements here, but about the knee-jerk reaction to eliminate everything in the name of simplicity. Minimalism does not mean nothingness. Instead, it is the minimum required to accomplish the task. If we cannot accomplish a meaningful task, then even the most clever interface design has no purpose, and is therefore unusable.

The key is to begin with a solid understanding of the design requirements. What are we trying to accomplish? Why? What are the benefits? Who will use it? Under what conditions? We should feel a certain anxiety about these questions. We need to challenge our initial assumptions, and ensure that we are driving at the heart of the matter. Misunderstanding the goal — or correctly understanding the wrong goal — makes it hard to optimize the design.

Once we have a laser focus on the purpose of the work, then we can begin to consider the interface. But here again we need to be minimalistic. We may be tempted to add some feature to make the design similar to existing designs for other things. However, because some people will be unfamiliar with those other things, it is better to make the design simple than similar.

A great example of minimalist design is the common light switch. The light switch is almost barbaric in its simplicity — all it does is turn a light on or off. But this is all that it needs to do. When I was a kid, I used to think that the dimmer switch in our dining room was cool because I could turn the lights down low and pretend we were at a fancy restaurant with candles on the table. But what is the point of turning on lights if they are not bright enough to illuminate anything? Even when I have a multi-stage lamp or a dimmer switch, I rarely do anything other than turn it on full power or turn it off. And for all those places where I do not have any other option, I have never felt deprived of the opportunity to achieve some intermediate level of illumination.

But the light switch offers more than just a way to turn on and off the light. It gives us information about the state of the light’s circuit. In a correctly wired switch, up means that power is flowing to the light, and down means that it is not. If the switch is up but we do not have any light, then the most likely cause is a blown bulb. Yes, the light switch is a debugging tool as well as a functional device. In addition to the up=on, down=off signaling, light switches abhor intermediate states. If we push the switch hard enough to get past a point, the switch springs the rest of the way and offers sensory feedback in terms of a satisfying click that tells us it has arrived at a resting point (i.e., that it is in a valid state). With all of these usability features focused on a simple application, no wonder the phrase “to flip a switch” has become idiomatic for “to do something effortlessly.”

When faced with a minimalist design, the feature nazis often protest that we have not left enough room for “user-friendly” customization. What if the customer wants to do something different than the simple on/off? I suppose this is where the idea of a dimmer switch came from.

Perhaps the idea of a dimmer switch does not seem like much of a crime to you. I admit that they generally are not hard to use. But let’s consider a slightly extreme case. A few years ago when we lived in the Chicago area we had a fancy master bedroom with one of those cathedral ceilings. At the peak of the ceiling above the bed there was a ceiling fan. The fan was great. On warm summer nights it added just enough circulation to the room to allow for comfortable sleep without having to crank up the air conditioner. But as much as I liked having the fan there, the switch was a nightmare.

Four buttons comprised the switch. The top button was for turning the light off and on, and for dimming it. The second button was for turning the fan off and on and adjusting its speed. The third switch changed the direction of the fan’s rotation (one direction to blow air down for a cooling effect, the other to recirculate the air in the room without blowing on us directly). The bottom switch turned all power to the fan and light on or off.

The first problem with this design was that these buttons all looked and felt the same – and did not change position when they were in the on or off state. As a result, it was hard to tell whether the light and the fan were off because the main power switch was off, or whether the main power switch was on but both the light and fan had been turned off individually. Thus, the simple act of turning on the light sometimes took as much as three button presses (cycle main power off and then on, press dedicated light power switch). This annoyance alone was enough that my wife and I had to establish some new etiquette for the light: never touch the main power switch. In addition, the sameness of the buttons made it easy to fumble them in the dark. On more than one occasion I accidentally turned on the light and woke up my wife when I had meant to turn on or off the overhead fan.

The next problem was with the two buttons that acted both as on/off switches and as dimmers. Both buttons functioned in the same way, so I will use the one for the light as an example. Pressing the button quickly cycled the power on or off. The switch had a memory that kept track of the last brightness level, so if you wanted to alternate between off and that brightness level (which was our normal preference), this was the way to go. However, the button was soft and squishy. Sometimes I would push the button thinking I had depressed it enough to turn on the light, but nothing would happen. As a result, I got in the habit of mashing the button and holding it there for a bit just to be sure. The problem was, holding down the button caused the switch to go into “dimmer” mode. That is, if the light was off, pressing and holding the button made it turn on at its lowest brightness level. Hold it for another half second and it would get a little brighter; keep on holding and it would cycle through six levels of brightness until it was at maximum power. Unfortunately, when the light was already on pressing and holding the button did not cycle the brightness, it only turned off the light. As a result, often I would attempt to turn on the light, only to find that I had held it too long. The light would come on at its weakest brightness. But then rather than allowing me to press and hold to increase the brightness, I would have to turn off the light, and try again. There were times when it took me several seconds to turn on the light in the room. I felt as if I was becoming hypertensive.

The end result of this design was that we had all of the customization we wanted – six different lighting levels, six different fan speeds, and the fan direction switch together gave us seventy two unique permutations. But I would have been much more satisfied with a traditional on/off switch for the light next to a dimmer switch for the fan (because sometimes it is nice to be able to adjust fan speeds). Incidentally, this setup is exactly what we had in the other bedrooms in the house – the ones where fixtures were a little less “high end.”

I tell this story not to illustrate how much I fumble with light switches, or to say that the switch in our master bedroom was particularly incomprehensible to me. I understood it, and most of the time I could make it do what I wanted. But sometimes it gave me grief. I did not tend to dwell on it at the time, but there were some real inconveniences. Looking back, I am a little surprised that I did not eventually replace the switch with something more simple, but perhaps it was not worth that much effort. I will say that ever since I have thought much less of that particular brand of ceiling fan.

So, less is more, and simpler is better. Sure, these are trite phrases. But then it is all the more amazing how rarely we actually live by them.