Caveat Emptor: I'm writing this article to clarify what I expect out of anyone who proposes a design and how to have a successful discussion about that design. I hope this will be useful to anyone I work with and I hope it will help any Microsoft interview candidates well more comfortable with our design questions.

When designing UI at Microsoft eventually someone will present the team with a mock-up of some proposal for the UI. From the presenter's perspective what is being offered is a *design* for some UI.

NOTE: I always have trouble parsing that word as a action ("design") or as a job title ("designer") when that word is not tied a specific field. And my issue with that action and job title is a long-running debate that shows no sign of ending soon and I plan one day to post an entry on that topic, but until then in this post I'm going to restrict myself here to its use as a noun.

Specifically, what I am writing "design" as an artifact of communication (as opposed to the artifact that is created from the design.) As a clarifying example, I am interested in the plans (diagrams, etc.) to build an airplane, not an airplane.

Back to the story: We are given a mock-up of a "design" for some UI. Maybe it's printed out, maybe it's emailed as a PNG file. In the end, we have received a drawing of some kind. I have no complaint that it takes the form of a drawing. It's entirely appropriate, but just not necessarily sufficient.

But is it a design? Is there enough there to say that one is looking at a proposed solution to a problem? or is it just a drawing? If it's really a design, we can have a productive conversation. If it's just a drawing, we're wasting our time.

Here's my simple set of questions I have for the designer.

  • What was the goal of the design?
  • How do we measure the degree to which the design has achieved that goal?
  • What problems from the perspective of the user are being solved?
  • What constraints & assumptions are incorporated into the design?
  • What are the key decisions that define this design?

If there are good answers to all the questions, the designer is doing great. If he's at least thought about those topics in a non-trivial way, even that's good. If someone is unable to quickly answer or show his thinking behind these questions, then probably we are looking at a weak design. It's probably a drawing, something that was created to look better or interesting or cool but ultimately a reworking of the surface of an existing problem or a half-developed thought.

Ultimately, for me a design (the artifact) boils down to: a rational plan that incorporates:

  • Goals - if you don't understand the point, why bother.
  • Measurement - if you don't have a way of distinguishing whether a design is achieving a goal then failure and success look alike.
  • Problems - From the user or customer's perspective, what is the itch to which this design is the scratch? From the solution perspective, what is the fundamental challenge & what things must we trade-off against each other?  
  • Constraints & Assumptions - We should, of course, challenge the constraints and assumptions, but not being aware of existence or incorporating them in our thinking is irresponsible.
  • Decisions - the art & fun of designing things for me is that given goals, problems, constraints, and assumptions one still have to decide among alternatives. If there were no decisions that had to be made, then from my perspective there wasn't any design (as a verb) occuring.

Summary

I've written about how I identify if a proposal has a rational approach (a thoughtful design). To me, any serious design has to meet this minimum bar. If someone claims to have designed something and can't show the thinking behind that design, then, in my opinion, there's no design there to talk about.

Further Reading

Industrial Design: Claims Without Substance 
http://jnd.org/dn.mss/industrial_desi.html

"Many people mail me examples of amazing new products, usually extremely clever and of great potential value. Many is the time I have visited design schools across the world to be shown wonderful examples of student and faculty work, each cleverly done, each accompanied by a long explanation of why the product solves some long-endured real problem. But do they really work? Do they really solve problems? Nobody knows. The designers simply assert that they do."

Great Design: What is Design (First Draft)  
http://www.joelonsoftware.com/design/1stDraft/01.html

"...If you have been thinking that there is anything whatsoever in design that requires artistic skill, well, banish the thought. Immediately, swiftly, and promptly. Art can enhance design but the design itself is strictly an engineering problem. ... Design, for my purposes, is about making tradeoffs."