Why 5 sketches? Why not 3?

When a team is embarking on a Five Sketches™ software-design project, they first agree on the problem statement—the setting in which they will sketch. Then each participant goes their own way to separately sketch five solutions. This takes time and effort.

Idea-generation effort
The effort to generate an idea varies. The first few are easy.

The first few ideas are easy—anyone can sketch one or two. Then comes the uncomfortable feeling of trying to force inspiration. Every designer experiences this feeling, and they’re used to it. But your Five Sketches™ participants aren’t used to it, and they haven’t learned that taking the time to do it will result in success, which affects their motivation. So, as smart people often do when faced with a problem, they’ll try to adjust the rules. They’ll try to bring fewer than five sketches.

What’s wrong with fewer sketches?

You may wonder: “If three or four participants each bring two sketches, that’s six to eight in total—isn’t that sufficient?” Fewer than five each is not enough. To understand why five is the minimum, let’s consider a few things.

No favourites

If a team has only one idea, the choice is simple: “Do we build this?” But this is an uncomfortable choice, because of the nagging question: “Are there any better choices?” And if a team has several ideas, in theory the choice can becomes: “Do we want this instead of that?” In practice, however, the theory doesn’t hold up because everyone defends their favourite idea, and everyone tries to have their favourite idea represented in the finished design. You may have you heard the expression: “A camel is a horse designed by a committee.” That’s the outcome when all favourite ideas get included without discarding or evolving anything. The easiest way to avoid having a favourite idea is to have many ideas—lots of ideas—from each participant. The requirement to each produce five sketches helps detach people from their favourite.

Elaboration and reduction

In the 2007 book, Sketching user experiences, Bill Buxton promotes a design process that involves generating lots of ideas, elaborating on them, and then filtering and reducing the number of ideas as people repeatedly choose between this and that. But there have to be things to choose from. In Five Sketches™, the initial independent sketching generates ideas, and then, after those have been shared, the mash-up sketching generates even more ideas. Through the experience itself, Five Sketches™ participants learn that it’s quite easy to have more ideas and better ideas, and that it’s essential to combine ideas and to borrow ideas from others. This takes the sting out of leaving behind many of the ideas. Buxton wrote: “One of the most positive forms of criticism is a better idea, and frequently that better idea would never have come about were it not for the idea that it replaces” (p.151). And experience tells us that any idea—even crazy ones—could inspire a better idea. The requirement to each produce five sketches helps people produce sufficient ideas to start with, even if they’re crazy ideas.

Parallel design

Doing the initial sketching independently is one of the cornerstones of Five Sketches™. There’s research to supports this. Generating ideas independently and then sharing them is called parallel design. Here are some studies that showed teams produce better results with parallel design:

  • Ball, L.J., Evans, J., and Dennis, I. (1994). Cognitive processes in engineering design: A longitudinal study. Ergonomics, 37(11), 1753-1786.
  • Buller, D.B., et al. (2001). Formative research activities to provide Web-based nutrition education to adults in the upper Rio Grande Valley. Family and Community Health 24(3), 1-12.
  • Macbeth, S.A., Moroney, W.F., and Biers, D.W. (2000). Development and evaluation of symbols and icons: A comparison of the production and focus group methods. Proceedings of the IEA 2000/HFES 2000 Congress, 327-329.
  • McGrew, J. (2001). Shortening the human computer interface design cycle: A parallel design process based on the genetic algorithm. Human Factors and Ergonomics Society Annual Meeting Proceedings, 603-606.
  • Ovaska, S. and Raiha, K.J. (1995). Parallel design in the classroom. Proceedings of CHI ’95, 264-265.
  • Zimmerman, D.E., et al. (2002). Integrating usability testing into the development of a 5-a-day nutrition Web site for at-risk populations in the American Southwest. Journal of Health Psychology.

So despite the lonely struggle of producing those initial five sketches, doing so helps participants produce better design outcomes.

So. Those are the reasons

Participants must always come prepared with at least five sketches that they produce independently. It makes it less likely they’ll hang onto their favourites at the expense of better ideas. It ensures they will learn that having lots of ideas is possible. It makes them more creative. And it provides the team with enough—barely enough—ideas to mash up and improve.

Success tip. Smaller groups must start with more than five sketches each. At five sketches each, three or four participants combined start with 15 or 20 sketches. For two participants to achieve with a similar starting number, they’d need eight sketches each. That task is beyond inexperienced sketchers, so if your participants are Five Sketches™ novices, recruit four participants.

Why sketch at all? Why not use computers?

Mock-ups and high-fidelity computer renderings have their place in the design process—especially to test and validate designs. But the initial generation of ideas is best done with a marker on paper.

That’s because the use of a marker improves creativity when generating appropriate ideas, by over 35%. This was reported in:

  • Oviatt, S., Cohen, A., Miller, A., Hodge, K., and Mann, A., (2012). The impact of interface affordances on human ideation, problem-solving and inferential reasoning. ACM Transactions on Computer-Human Interaction. 9(3):22.

Even software such as Sketch, Figma, or Balsamiq Mockups—wireframing tools that help you produce and animate lower-fidelity images—won’t help you generate as many ideas as a pen on paper. That’s because, as Sharon Oviatt and her co-authors explain, a computer interface affects how people’s brains generate ideas. There are other benefits to low-fidelity images, including ones generated by Balsamiq’s product, that aren’t directly related to the goals of a Five Sketches™ design session. UIE’s post, Five prevalent pitfalls when prototyping, explores the nuances that will help you see why Five Sketches™ participants need to sketch on paper during the idea-generation stage of design.

Some research shows observers find it easier to iterate and critique low-fidelity images—ones that are sketched by hand rather than high-fidelity images produced in Photoshop or Illustrator, or mocked up in computer simulations. This benefit applies to all participants in a Five Sketches™ session, as they evaluate all ideas and iterate their sketches.