There’s a thread on Quora about how to define a designer’s ideal range of knowledge.

Here are the dimensions we look at:

  1. Writing: Can they think and communicate clearly? Writing skills are critical to UI.
  2. Interface design: Can they organize elements in 2D space so that the arrangement is meaningful, clear, and instantly understandable? Can they organize elements in time (navigation, flows, steps) in a way that minimizes uncertainty and feels efficient?
  3. Product: Can they appreciate the problems and desires our customers have and turn that understanding into business value? In other words, do they know what matters and what doesn’t matter to customers and stakeholders?
  4. Development: Are they able to code their designs in HTML/CSS? Can they go further and integrate their designs into the application source code? Can they talk shop with programmers?
  5. Character: Are they a nice person with a good motivation?

Of course it isn’t necessary for everyone to kill on every point (except #5). But I think you can tell a lot about a company’s design culture by looking across these dimensions.