User expectations refers to the consistency that users expect from products. Interaction design is very concerned with this topic. For example, our user expectations for traffic behavior is one of the more consistent ones because it is governed by traffic laws that are enforced. Software, or even worse small consumer electronics, on the other hand, can have widely varying degrees of consistency.

A good rule of thumb or design rule to use in interaction design is to follow the "Principle of least astonishment". A commonly noted sign of poor usability and human factors due to the violation of user expectations is when signs are needed for common things like doors. This was made famous by Donald A. Norman in his seminal book The Psychology of Everyday Things . There is also a website devoted to such Bad Designs [1].

External links

• User Expectations in a World of Smart Devices, by Mike Kuniavsky
• Managing User Expectations, by John Rhodes
• How to Avoid Foolish Consistency, by Scott Berkun