USABILITY 101 (aka LEMErS)
Learnability: How easy is it for users to accomplish basic tasks the first time they encounter the design?
Efficiency: Once users have learned the design, how quickly can they perform tasks?
Memorability: Do users remember the interface/brand/product? When users return to the design after a period of not using it, how easily can they reestablish proficiency?
Errors: How many errors do users make, how severe are these errors, and how easily can they recover from the errors? Is the error acknowledged elegantly?
Satisfaction: How pleasant is it to use the design? Are there pleasant surprises?

















