A good design critique

How do you thoroughly critique a design without crucifying the designer? What are ways of critiquing that result in better designs, rather than defensive justifications?

Scott Berkun explores a model for design critique in a detailed post, but I'm interested in the little stuff that works for your design team in day-to-day practice.

At Cooper, our teams often work together for a year or more. It is important for us to create a dynamic of cooperation, but great design often happens when we push on assumptions and challenge the first iteration. We want to encourage this critique, but make sure that it doesn't derail the meeting.

Why is that good?

It's pretty common to hear a skeptical Cooper designer begin a critique with some variant of the question, "Why is that good?" Many ways to express disagreement have negative effects on the meeting or relationship. "That won’t work because," or "But what about." These tend to bring momentum to a halt. Designers must stop, defend their ideas, or chase objections.

As anyone who has faced a blank whiteboard knows, once the ink gets flowing it is important to run with it and see where the idea goes. Communication strategies of design partners can enhance or detract from this process. By asking to see the goodness, we focus on enlightenment, encouraging our partner to help us see what they see. Also, asking an open-ended question is an acceptably naïve way of pushing your design partner to step up and show you what is going on in their mind.

At the core, we want our teams to feel comfortable in expressing healthy disagreement, and to focus on clarifying rather than justifying.

What are ways that your team has developed to critique design while maintaining harmony on the team?