Most usability tests culminate with a short questionnaire that asks the participant to rate, usually on a 5- or 7-point scale, various characteristics of the system. Experience shows that participants are reluctant to be critical of a system, no matter how difficult they found the tasks. This article describes a guided interview technique that overcomes this problem based on a word list of over 100 adjectives. — DAVID TRAVIS, MARCH 3, 2008, UPDATED 22 JULY 2009.
Measuring user satisfaction
A common mistake made by novice usability test moderators is to think that the aim of a usability test is to elicit a participant’s reactions to a user interface. Experienced test moderators realise that a participant’s reaction is just one measure of usability. To get the complete usability picture, we also need to consider effectiveness (can people complete their tasks?) and efficiency (how long do people take?).
These dimensions of usability come from the International Standard, ISO 9241-11, which defines usability as:
“Extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use.”
The ISO definition of usability makes it clear that user satisfaction is just one important dimension of usability. People may be well disposed to a system but fail to complete business-critical tasks with it, or do so in a roundabout way. The three measures of usability — effectiveness, efficiency and satisfaction — are independent (PDF document) and you need to measure all three to get a rounded measure of usability.
Continue reading this article at: Measuring satisfaction: Beyond the usability questionnaire.