The connectors and attachments suggested this pump would fill North-American and European tire tubes as well as air mattresses, soccer balls, and basketballs.

But the thing is, neither the pump’s owner nor I were able to make it work. We couldn’t pump up my bike tires.

Was it me? Was it the pump’s owner? Or was it the pump’s design?

If the user can’t use it, it’s broken (…or it may as well be).

Deliver working software frequently [in short sprints that last] from a couple of weeks to a couple of months, with a preference to the shorter timescale.

Working software is the primary measure of progress.

From discussions with other practitioners, I know that software teams can get dogmatic about the above principles, and often work in sprints of one, two, or three weeks in duration to ensure they deliver frequently. Since the classic software-development problem has been delivering the wrong features too late, I understand the desire to deliver working software frequently, with more frequent opportunity for customer feedback.

When the “deliver frequently” principle becomes a fixation, though, other things can get bruised in the rush to produce working software. Consider design and usability research. Sometimes a system’s features are complex and interrelated. Sometimes an elegant and simple solution is elusive. (Technical limitations can contribute to this.) Sometimes a weak design needs testing to make sure it is usable. To ensure design and usability work gets the time it needs, this work is often moved to preceding and successive sprints. This sets the designer and usability analyst apart from the rest of the team.

Here are my ideas to help design and usability work integrate better into short sprints:

• Ensure a designer understands the entire set of features before the first sprint. Ask for a broad-strokes design for the whole, and share it, so the team has a vision for the user experience. Before a sprint completes, compare the working software to the user-experience vision.
• Agile tries to keep the deliverable as simple as possible, but simple features from different sprints may not combine into a good user experience. This is a defect, to be fixed like any other bug, before the sprint completes.
• Ensure that usability and design bugs are resolved, by testing with users to validate the changes.
• When you need work done that substantially shapes the user experience but that is not related to a specific feature, regard this user-experience work just as you regard database, architectural, or other foundational work. Foundation work is easier for the team to prioritise when planning a sprint.

The above suggestions work within the “deliver working software frequently” principle. I have another suggestion that pushes at Agile’s envelope.

I think the words “working software” are too restrictive. In my opinion, there are other deliverables that are equal to working software, especially for teams that use very short sprints. A deliverable such as a paper prototype or a low-fidelity interactive prototype is equal to a piece of code, and allows team members—all team members on an Agile team—to focus on design, prototyping, and validation together instead of making a designer or usability work one sprint ahead or one sprint behind the rest of the team.

In one pair of light switches, the left switch controlled a lamp to the right, and the right switch controlled a lamp to the left. The previous resident’s solution to this poor mapping was to put a red dot on one of the switches, presumably as a reminder. I put up with that for about 3 days, and then it was time to fix the mapping.

Now, the left switch is for the lamp on the left, and the right switch is for the lamp on the right. That’s natural mapping.

If you want to read more about natural mapping, check out this blog about interaction design and usability. It presents a classic natural-mapping problem: on a kitchen stove, which dial controls which burner?

Meanwhile, at my home there are other problems with light switches, but they aren’t about mapping. In one case, the light switch is far from the door, so at night I must cross a dark room to reach the switch. In another case, the light over the stairs is controlled by two switches that are improperly wired, so both switches must be in the “on” position. If you guessed that one switch is upstairs and the other downstairs, you’re correct. To light the stairs, often I must run up or down the dark staircase to flip the switch.

All this is both amusing and irritating and, as I already said, a daily reminder that usability doesn’t just happen. To get it right, usability takes planning and attention during implementation.

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I imagine the metal inserts in the wooden banister (see the video, above) are detectable warnings for people who are visually impaired, but that’s only a guess. If you watch the video again, you’ll see that the metal inserts do not occur at every bend in the staircase.

Whatever the intent, the banister fully met my needs.

A sudoku puzzle consists of nine 3×3 squares, sprinkled with a few starter numbers. The player must fill in all the blanks by referring to the numbers that are already filled. A number can only occur once in each row of 9, each column of 9, and each 3×3 square.

I regularly complete difficult sudoku puzzles, but this easy one—more starter numbers makes the puzzle easier—was taking much longer than I expected.

I soon realised that my slow performance was due to a design decision by the graphic artist!

In the original puzzle, shown at left, the graphic designer used  shading  for all the starter numbers. In my reformatted version, on the right, I used shading to separate the 3×3 squares. Both puzzles also use thicker lines to separate the 3×3 squares.

The shading for starter numbers, on the left, is unfortunate because it interferes with the player’s perception of the nine 3×3 squares. Instead, players perceive groups of numbers (in diagonals, in sets of two, and sets of five).

I assume the designer’s intention was to help identify the starter numbers. Regardless of the designer’s intention, the human brain processes the shading just as it processes all visual information: according to rules that cognitive psychologists call gestalt principles. A sudoku player’s brain—any human brain—will first perceive the shaded boxes as groups or sets.

In sudoku, the grouping on the left is actually meaningless—and counterproductive. However, since the brain applies gestalt principles rather involuntarily and at a low level, the grouping cannot easily be ignored. The player must make a deliberate cognitive effort to ignore the disruptive visual signal of the original shading. This extra effort slows the player’s time-on-task performance.

You can check your own perception by comparing how readily you see diagonals and groups in both puzzles above. On the left, are you more likely to see two diagonals, two groups of five, and many groups of two? If you are a sudoku player, you’ll recognise that these groupings in the puzzle are irrelevant to the game.

If you like, you can print the puzzles at the top, and give them to different sudoku players. Which puzzle is faster to complete?

Interested in gestalt principles? I’ve blogged about the use of gestalt principles before.

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:

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:

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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:

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:

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?

The person I was observing was visually impaired and had his GUI enlarged by about 1000% or more. As he attempted to troubleshoot his wireless connection, he was very rapidly scrolling horizontally and vertically in order to read the text and view the icons in the Wireless Connection Status dialog box. The hugely enlarged GUI flew around the screen. His screen displayed only a small portion of the total GUI, but he never lost his place.

In contrast, I lost my place repeatedly. I couldn’t relate the different pieces of information, so what I saw was effectively meaningless to me much of the time. His spatial awareness—his ability to navigate quickly around a relatively large area—was clearly more developed than mine.

I could not keep up with all of the text, either, even when he was reading it to me out loud: ”It says ‘Signal Strength” is 4 bars, but it won’t connect. See?” (Well, actually, I didn’t see.) Though I’m very familiar with this dialog box, I could only read the shorter words as they flew by on screen. The larger words were illegible to me. His ability to read rapidly-moving whole words when only parts of them were visible at any given instant was much more developed than mine. I felt sheepish about being functionally illiterate under these conditions.

It was interesting to see how my own user performance depends on such a narrow range of conditions. I need to see the whole word and its context. I need to see at least half the dialog box at once. And, if the image is moving, it must be moving slowly.

• The user’s display size.
• The soundscape.

Large displays < one salary

Users 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.

Again: 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.

If you ask me, I’d say: “Not anywhere near as tiny as they are.”

I’d also say: “If you make an app for iTouch or iPhone, ensure that the keyboard flips into a larger, wider version when users rotate the device on its side.”

The illustration on the left?  Or the photo on the right?

According to Frank Long’s research paper, Real or Imaginary: The effectiveness of using personas in product design, photos are better than illustrations. Teams whose user personas include a photograph of the persona produce designs that rate higher when assessed with Nielsen’s heuristics for UI design.

Frank Long compared the design output of three groups, drawn from his students at National College of Art and Design (NCAD) in Ireland, in a specific design project. Over the five-week project, two groups used user personas of different formats. One group was the control group, so they worked without user personas. The experiment looked for differences in the heuristic assessments of their designs.

Photos—versus illustrations—are one of the ways I’ve engaged project teams with the user personas that I researched and wrote for them. Here’s a teaser:

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