When Is It OK to Be Inconsistent in User Interface Design?
Summary: Consistent design enhances learnability and is usually best for usability. But if the problem you're solving is sufficiently different, then inconsistency may be better.
Kathryn Whitenton is a former NN/G employee who worked with clients to evaluate the user experience and information architecture of websites in a variety of industries including technology, telecommunications, and media, as well as corporate intranets. She conducted usability research, eyetracking user research, and studies of users on mobile devices in the United States, Europe, Asia, and Australia. Her user studies included general audiences as well as specific consumer types, business segments, children, and seniors.