Measurable Human Factors to Evaluation
Time to learn: How long does it take for typical members of the user community to learn how to use some specified functions?
Speed to performance: How long does it take to carry out the specified task?
Rate of errors by users: How many and what kinds of errors do users make in carrying out the specified task?
Retention over time:: How well do users maintain their knowledge after an hour,. A day, or a week?
Subjective satisfaction: How much did the users like using various aspects of the system?
(Ben Shneiderman, 1998, Designing the user interface, Addison-Wesley)