Display Information that Helps Users Make Decisions


What you’re looking at is the dashboard of a 2009 Honda CRV. I leased this car almost a year ago when I was commuting down to a project in Silicon Valley.

If you perform a squint test on this interface, what do you see? The speedometer, the tachometer, and maybe the outline of the car. What you aren’t also seeing in this picture is the steering wheel, which obscures a considerable portion of the dashboard, as do your hands on the steering wheel.

What you can’t see very well is the fuel gauge. See it there, second from the bottom. Countless times with this car, the fuel light has come on unexpectedly because the fuel gauge is completely minimized, especially when compared to the tachometer, which, because this is an automatic car, the information it displays is almost never needed.

If controls are choices, then displays certainly are as well. Interface designers need to take a cue from the design of games here and present information that players (users) need to make decisions. With a game, users are always scanning the board/screen, using the information provided to make the next, best decision. The same is true for applications and control panels. Tell me what I need to know, when I need to know it.

What a gauge or any indicator on a dashboard should display is either status (what is happening now, e.g. my radio station, the time, signal strength, wash cycle, etc.) or resources: how much of a particular thing I have remaining. Could be fuel, could be unread messages, could be time. Figure out what the most important resources and statuses are, filter by the frequency of use, then make those indicators the most prominent. For example, the engine temperature might be the most important gauge on the dashboard, but it’s used far less frequently than the speedometer.

It’s not rocket science, but if this dashboard is any indication, the basics sometimes get overlooked. Emphasizing the important is done all the time with controls, where the “hero control” (the one used most often) has prominence.

The Honda CRV dashboard is clearly a case where the industrial designers of the car had little or no interaction with the designers of the UI. Someone told the UI designers, “You have to display this stuff in this tiny screen. Go!” whether or not it made sense for something as essential as the fuel gauge to be there or not. This doesn’t excuse the de-emphasis of the fuel gauge over, say, the trendy hypermiling indicator at the top of the display, where it would have been logical, were I the interface designer, to put the fuel gauge.

In a more perfect world, the industrial, interaction, and interface designers would have all sat down to plot out the dashboard, taking into consideration nuances like what the steering wheel would hide and visible sight lines; what the most important information to display is, and when; and what displays would be physical gauges, and which would be on a digital display. A functional cartography for information. But alas, we live in imperfect times, and so occasionally, I almost run out of gas while driving.