Agile design and usability: Will a prototype do?

The Agile Manifesto includes twelve principles. These two are related:

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.

It works!

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.

Sketch, wireframe, prototype

Over the past month, I’ve come across the same discussion several times: “When designing a website or product, do you use wireframing or prototyping?”

The first part of my answer is: “Make sure you sketch, first.”

At the design stage, sketching, wire-framing, and prototyping are not equal. Sketching is useful at the divergent phase of design because it lets the design participants express and capture lots of different ideas quickly and anywhere that pen and paper will work. Nothing is as fast as running a pen across a sheet of paper to capture an idea—and then another, and another. And since sketching is intentionally rough, everyone can do it.


Responding to Œ the problem statement, first  saturate the design space with lots of ideas, and then Ž analyse and rapidly iterate them to  a design solution.

I also believe sketching is great for the convergent phase of design, but there are potential hurdles that design participants may encounter. It can be challenging to convey complex interaction, 3D manipulation, transitions, and multi-state or highly interactive GUI in sketches without learning a few additional techniques. This is unfortunate, because having to learn additional techniques reduce the near-universal accessibility of sketching.

The second part of my answer, therefore, is that “if you need to learn additional techniques to make sketching work, feel free to choose wireframes or prototyping as alternatives when there are compelling reasons to do so.”

I should point out that the three techniques—sketching, wireframing, and prototyping—are not mutually exclusive. Wireframes and paper prototypes can both be sketched—especially for simple or relatively static GUI designs.

There are no validity concerns with the use of low-fidelity sketches, as these readings show:

From napkin to Five Sketches™

In 2007, a flash of insight hit me, which led to the development of the Five Sketches™ method for small groups who need to design usable software. Looking back, it was an interesting journey.

The setting. I was working on a two-person usability team faced with six major software- and web products to support. We were empowered to do usability, but not design. At the time, the team was in the early stages of Nielsen’s Corporate Usability Maturity model. Design, it was declared, would be the responsibility of the developers, not the usability team. I was faced with this challenge:

How to get usable products
from software- and web developers
by using a method that is
both reliable and repeatable.

The first attempt. I introduced each development team to the usability basics: user personas, requirements, paper prototyping, heuristics, and standards. Some developers went for usability training. In hindsight, it’s easy to see that none of this could work without a formal design process in place.

The second attempt. I continued to read, to listen, and to ask others for ideas. The answer came as separate pieces, from different sources. For several months, I was fumbling in the metaphorical dark, having no idea that the answer was within reach. Then, after a Microsoft product launch on Thursday, 18 October, 2007, the light went on. While sitting on a bar stool, the event’s guest speaker, GK Vanpatter, mapped out an idea for me on a cocktail napkin:

  1. Design requires three steps.
  2. Not everyone is comfortable with each of those steps.
  3. You have to help them.

The quadrants are the conative preferences or preferred problem-solving styles.

I recognised that I already had an answer to step 3, because I’d heard Bill Buxton speak at the 2007 UPA conference, four months earlier. I could help developers be comfortable designing by asking them to sketch.

It was more easily said than done. Everyone on that first team showed dedication and courage. We had help from a Vancouver-based process expert who skilfully debriefed each of us and then served us a summary of remaining problems to iron out. And, when we were done, we had the beginnings of an ideation-and-design method.

Since then, it’s been refined with additional teams of design participants, and it will be refined further—perhaps changed significantly to suit changing circumstances. But that’s the story of the first year.