Auto-correct a touch-screen problem

For the past few months, I’ve been taking an average of 1.6 flights per week on commercial airplanes. Most of these offered seatback entertainment, so I could watch the TV show or movie of my choice, or listen to satellite radio while reading. Touch-screen controls are easy to use because they let me touch—or tap—the item or the control that I want. By using the touch screen, I can select a program, adjust the volume, skip the next song, and so on.

One thing I’ve noticed is that about ¼ of seatback touch screens are poorly registered. By registration I mean that the system and the user agree on where the user is tapping or touching the screen:

An illustration of registration

I recorded a video of two common tasks for a seatback entertainment system: selecting the language and adjusting the volume. As you can see, the registration is off, so I initially get the French interface instead of the English, and I must press an unrelated button to adjust the sound:

The registration error is significant. My fingertip tapped about 2 cm left of the centre of the EN button. The larger the registration error, the harder to tap a small target—as was the case with the volume controls in the video, above, where I appear to be tapping the Fast-Forward button. On more than one flight I have unintentionally increased the sound to painful levels while attempting to lower the volume!

A system such as this could be made to detect and auto-correct poor registration. If we assume that repeat taps on a blank location indicates poor registration, the software could:

  1. After several repeat taps, select the nearest target—a reasonable guess—even if it is a centimetre or two away from the user’s tap.
  2. Ask the user to confirm the guess. “Did you mean [this one]?”
  3. If the user confirms, calculate the amount by which to correct the registration, and then fix the registration error.

This solution requires a screen—perhaps the start screen—whose choices are spaced far apart, so the system can detect when the user appears to be tapping a blank space:

Tapping a blank space (at right)

If user testing were to show that auto-correction needs human involvement, after calculating the registration error, the system could ask the user to check the corrected registration. For example:

Confirming that the registration is correct
Are you there? Please tap the green circle.

I haven’t done any testing of this idea, nor have I given this much thought, so I’m certain there are many more and better ways to auto-correct a registration problem on a touch screen. I merely wanted to identify one possible solution in order to get to the next point: the need to consider the business drivers when deciding to address (or deciding not to address) a usability problem.

Everything costs money

Fixing this problem—it’s a real problem, you’ve seen the video—would cost money. If the following can be quantified and evaluated within a framework of passenger-experience goals, there may be a convincing business case:

  • Not every passenger can work around a registration problem. Those who cannot would be unable to use the entertainment system. When everyone else gets a movie, how does the passenger with a failing system feel?
  • If a failed entertainment system is perceived as a negative experience, will passengers blame the touch-screen/software manufacturer or blame the airline? I’m sure you can imagine the complaint: “I sat there for hours without a movie! It’s the airline’s fault.” What’s the likelihood that this will cause churn (passenger switches to another brand next time)?
  • Based on the screens I’ve seen, some frustrated passengers must use hard objects that scratch and even gouge the touch screen. Are they trying to force the screen to understand what they want? Are they vandalising the screen? What’s the cost of replacing a damaged or vandalised screen?
  • A scratched screen is like graffiti. It affects every subsequent passenger in that seat. Do vandalised screens affect the airline’s goal of attaining a particular passenger rating for perceived quality or aesthetic experience?
  • The in-flight entertainment system was implicated in a catastrophic Swiss Air crash near Peggy’s Cove about a decade ago. Would a fix to the touch-screen registration problem incur prohibitive safety-testing costs?

Designing and influencing user performance

When designing the user experience of software, UX- and Development teams often focus on how the user interface supports user performance, because that’s within their locus of control. Once the product is in the wild, environmental factors may reduce user performance despite the team’s best product-design efforts. But I believe it’s possible for a UX team to also influence the environment in which their products get used. Consider two of these:

  • The user’s display size.
  • The soundscape.
Large displays < one salary

The environment affects user performanceUsers of all ages and genders are more effective at performing search tasks and comparison tasks (Tao Ni et al, 2006), and more effective at spatial tasks, when they use large displays. Mary Czerwinski et al, reported a 12% significant performance benefit (2003). However, when given a choice, people don’t want very large displays on their office desks; they opt for medium-sized displays instead. One study showed that older users least prefer large displays but stand to gain the most performance benefit. (This study was done before multi-monitor arrangements became common.)

A 12% improvement in performance suggests that 7 people with large displays could theoretically do the job of 8 people with medium displays. How many large displays could your office buy for one person’s salary every year? For business-to-business sales and especially for enterprise-wide software implementations, there’s a place for sales teams and proposal writers to mention the business case for larger displays.

Call it what you want—innovation, thinking outside the box, providing solutions—your UX-Design team can work with the Sales and Service/Implementation teams to ensure customers get solutions that include better hardware choices.

Speak less clearly, please

A half-decade of research by Dr Sabine Schlittmeier has expanded on what common sense told us: it’s harder to concentrate when others are chatting in the background. Schlittmeier found that when background speech is louder and more intelligible, it negatively affects verbal short-term memory, sustained attention, and verbal-logical reasoning. When I asked her what techniques have been shown successful, Schlittmeier told me that a masking sound, such as music or talk radio, is not objectively effective because the higher level of background sound has detrimental cognitive effects, but subjectively people feel this is effective. She added that there’s a measurable benefit to:

  • Shifting high-concentration work to times when fewer people are around.
  • Doing high-concentration work in single offices.

I suppose working remotely—from a quiet home—is a variation of these solutions.

I also asked, “What one thing, if handled differently, would most improve the way people experience noise at work?” Schlittmeier said it’s not about one thing. She recommended attacking problem sound from all dimensions at once: loudness, frequency characteristics, sound production, transmission, and so on.

The way I read the research results, reducing background speech to a soft, unintelligible noise could result in a 10% to 25% decrease in memory errors and logic errors, and an 18% increase in attention span. What Schlittmeier hasn’t provided is data about overall productivity improvement, without which it’s harder to make a business case for spending on office-noise abatement.

But there are other ways to mitigate the background office noise that affects your users, and you may be able to influence how your customers approach that problem.

A box that promotes wide screeens or headsetsAgain: call it what you want—innovation, thinking outside the box, providing solutions—your UX-Design team can work with the Marketing team to influence the environment through traditional marketing. Imagine a business-to-consumer product that is designed to work even better with a (noise-cancelling) headset—and which is depicted in use with headsets in the marketing messages and on the packaging.