Usability factors include

"Learnability: The system should be easy to learn so that the user can rapidly start getting some work done with the system.

"Efficiency: The system should be efficient to use, so that once the user has learned the system, a high level of productivity is possible.

"Memorability: The system should be easy to remember, so that the casual user is able to return to the system after some period of not having used it, without having to learn everything all over again.

"Errors: The system should have a low error rate, so that users make few errors during the use of the system, and so that if they do make errors they can easily recover from them. Further, catastrophic errors must not occur.

"Satisfaction: The system should be pleasant to use, so that users are subjectively satisfied when using it; they like it." (Nielsen, 1993, p. 26)

Usability Assessment Testing

A usability assessment test is typically performed to uncover as many usability issues as possible in the device/user interface, often leading to suggestions for design improvements. It typically includes

Product selection, investigation, reading, and task analysis
Test design, preparation, and human subjects approval for some
Subject recruitment and permission
Subject preparation (introductory script)
Careful observation as each subject attempts to perform tasks
Follow-up interview
Analysis of data, reading, and reporting

Resources for Student-Developed Usability Tests

Module on Usability: jcflowers1.iweb.bsu.edu/rlo/modusability.htm
Usability Research Assignment: jcflowers1.iweb.bsu.edu/rlo/510projectusability.htm
Student Usability Reports: jcflowers1.iweb.bsu.edu/rlo/usabilityreports.htm
Links on the Study of Using Technology: jcflowers1.iweb.bsu.edu/rlo/linus.htm
Grad Online Course: Tech Use & Assessment: jcflowers1.iweb.bsu.edu/510intro.htm

Articles on Usability Testing in Technology Education

Flowers, J. (2005). Usability testing in technology education. The Technology Teacher, 64(8), 17-19.
Flowers, J. (2000). Activities that teach about using technology. TTTe
Flowers, J. (1999). An outline for the study of using technology. J. of Industrial Technology, 15(2).

Books on Usability Testing

Barnum, C. M. (2002). Usability testing and research. NY: Longman.
Nielsen, J. (1993). Usability engineering. San Diego, CA: Morgan Kaufman
Rubin, J. (1994). Handbook of usability testing: How to plan, design, and conduct effective tests. NY: Wiley Technical Communication Library.