Usability ECE 695 Alexander J. Quinn 3/21/2016

Today Midterm Review 5 facets of usability

Five facets of usability Learnability Efficiency Memorability Errors Satisfaction

learnability “The system should be easy to learn so that the user can begin working quickly.” Credit: Jakob Nielsen, Usability Metrics: Tracking Interface Improvements, Interface, November 1996

efficiency “The system should be efficient so that once the user has learned it, high productivity is possible.” Credit: Jakob Nielsen, Usability Metrics: Tracking Interface Improvements, Interface, November 1996

memorability “The system should be easy to use and remember, so that the casual user can return to it after not using it for a time and still know how it works.” Credit: Jakob Nielsen, Usability Metrics: Tracking Interface Improvements, Interface, November 1996

errors “The system should have a low error rate, so users will encounter few errors; those they do encounter should be easy to recover from. Further, catastrophic errors mus not occur.” For our purposes, we will focus on human errors. Is it structured to mitigate inevitable limitations in human cognition and memory? Can you gracefully recover from a human error? Credit: Jakob Nielsen, Usability Metrics: Tracking Interface Improvements, Interface, November 1996

satisfaction “The system should be pleasant to use.” Credit: Jakob Nielsen, Usability Metrics: Tracking Interface Improvements, Interface, November 1996