The phrase "an usability" is not correct in written English.
The correct article to use is "a" because "usability" begins with a consonant sound.
Example: "A usability test is essential for improving user experience."
Alternatives: "a user-friendliness" or "a usability factor."
We demonstrated the efficacy of our system by means of an analytic evaluation (comparing it with others available on the web), an usability evaluation made by expert users (students adequately trained) and an experimental evaluation with 34 participants.
We prepared these issues based on (i) usability problems found in an usability inspection that we performed in different ERP systems available in the market; and (ii) the most common usability problems mentioned in the literature related to the domain of ERP systems.
Healthcare professionals were invited to participate in a workshop about diabetes before study start and to fill out an usability questionnaire at the end of the study.
Use "A" when u makes the same sound as the y in you: a union, a unicorn, a used napkin, a usability study.
It's not a huge issue, although it seems a bit odd from a usability perspective.
Though it became a cultural phenomenon and leapfrogged the Atari 2600, from a usability perspective, NES was a failure.
A business might want a usability researcher to go out and talk with users and examine what they're comfortable with.
A usability analysis is a necessity to evaluate and promote the usability of the web sites of the public institutions.
This chapter focuses on the planning of a usability study with a paper prototype.
In addition, a methodology for developing a usability index of consumer electronic products was proposed.
Whether on iPhone, iPad, or the Mac, their apps brings a usability and elegance to an otherwise ugly medium.
