## Gestalt principles hindered my sudoku performance

Last week, while waiting for friends, I picked up a community newspaper in hopes of finding a puzzle to help me pass the time. I found a sudoku puzzle.

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.

## Speed sketching vs. art/perfectionism

For a Five Sketches™ design session, I ask design participants to bring at least five substantially different ideas to the table, in the form of sketches. A common initial reaction is: “…But I can’t sketch!”

Many design participants believe they cannot draw. To be honest, I believe that about myself. People who feel they cannot draw tend to extend that belief to encompass design sketching, as well. However, I have learned to distinguish between drawing (below, left) and sketching a software design (below, right).

Software design does not require drawing, only sketching. From experience, I can tell you that sketching is easy once you realise that the goal is to produce only rough and low-fidelity ideas, not decorative and high-fidelity pictures.

Occasionally, I encounter a design participant who has trouble with sketching. I once had a participant who was so self-conscious of her sketching ability that she was paralyzed during the rapid iteration phase, when the design participants are quickly mashing up the sketches with borrowed and new ideas to produce additional sketches. I noticed that this participant was always busy—talking or wiping the board or replacing the snacks—but never sketching. This avoidance, and the underlying mental block, was an impediment to the whole team. Like all generative design processes, Five Sketches™ relies on its participants to saturate the design space with ideas. If a participant isn’t participating, it increases the project risk.

To pre-empt this mental block and to reduce the project risk, during Five Sketches™ training, I now introduce a quick speed-sketching exercise. Speed sketching is a race against the clock. With pen and paper ready, before each round, I give the participants five seconds to think, and then:

• 10 seconds to sketch a cell phone.
• 8 seconds to sketch a sandwich.
• 6 seconds to sketch an airplane.
• 4 seconds to sketch a ship.
• 2 seconds to sketch a house.

After each sketch, the participants look at the other sketches. I ask them to identify the details that make the sketched object recognisable. There isn’t time to draw a high-fidelity rendering, so the sketches are rough and have few details.

Interestingly, with few details the sketched objects are still clearly recognisable. Participants learn that detail and fidelity aren’t needed. By the last round of sketches—the “2 seconds to sketch a house” round—participants have seen that everyone’s ability to produce sketches is about equal, and they usually conclude: “I sketch well enough for others to grasp my ideas.” Generative design requires lots of ideas—disposable ideas—not fancy drawings.

Jason Santa Maria says a similar thing in his Pretty Sketchy blog post, in which he declares that sketching is not about being a good artist; sketching is about being a good thinker.

## Design and engineering culture

I’m sure Douglas Bowman’s blog last week was widely read. His post was a kind of public exit interview, titled Goodbye Google.

As Bowman left Google, he pointed out the pro-engineering bias in its approach to problem solving—including problems of design. Two of several examples he gives:

[…] a team at Google couldn’t decide between two blues, so they’re testing 41 shades between each blue to see which one performs better. I had a recent debate over whether a border should be 3, 4 or 5 pixels wide, and was asked to prove my case. […]

Bowman would like to see more weight put on design principles. His blog includes a link to Wikipedia’s article on design elements and principles, which lists:

 • unity • harmony • contrast • balance • repetition, rhythm, pattern • variety, alternation • emphasis, dominance, focal point • proportion, scale • functionality • attraction • artistic unity • genuineness in media and form • proximity • colour

I don’t think design principles are beyond an engineer. I do think engineers need to be taught how—and when—to think about these details.

As we discovered during the development of Five Sketches™, this kind of detail is often outside the comfort zone of an engineer. However, I can affirm that even engineers who initially produce work with little design insight or creativity have managed to astonish me with amazing design results within a year. And that’s after only occasional participation in Five Sketches™ design sessions.

So, yes, engineers can learn to participate in design, with success and predictability, though I would caution that Five Sketches™ works for engineers because it was developed for and with them, to meet their needs.

At Google, to bring about such a cultural change, Bowman would have needed the unwavering support of at least one senior executive. Even then, as Bowman himself acknowledged in his goodbye message, a company as large as Google does not change direction easily.

If you liked this post, read about how a company’s use of social media influences its corporate culture.