Good design is …

Good design is knowing which characteristics of your Web site or product are the most important, and which ones you are willing to give in on. If you are clear on the goals, success will always come from planning enough time in your schedule to think through the trade-offs of a wide set of alternatives. Consistency is a potential means for success, but not success itself.

Scott Berkun

Berkun provides five great ways to help decide on how consistency may help – or hinder – your goals in designing an interface. Sometimes designers find it expedient to reuse content or standardize an experience, because they as the designer are able to map a more cogent pathway. The end user, however, may find themselves trying to learn a system of interpretation while gaining no further value other than the interpretation itself. Here are the five rules of thumb, in Berkun’s own words:

  1. Begin by reusing existing controls or concepts in your sketches and prototypes unless your goals include changing a specific user task or behavior, start with as much consistency as you can. Reuse of working concepts is good. Style guides are of great value here in helping you to reuse as much existing knowledge and good design work as possible.
  2. If your sketches and prototypes aren’t working in user studies or other evaluations because of the failure of existing concepts, try to grow an existing concept to cover the new situation you have. If you change the behavior of a control, apply that change everywhere the control is used. If you change a concept, consistently apply that change.
  3. If you can’t extend what you have to solve the problem, go and design a new widget or concept to solve your problem.
  4. If you have to use special cases (local optimization of a widget that isn’t used everywhere), make sure it’s the best trade-off you have.
  5. Always ensure that user success at tasks takes precedence over abstract design consistency.