ABSTRACT
There is thus an urgent need to establish a cohesive and integrative model for usability measurement. Such a model should provide at least two things: (1) clear definitions of the concept of usability and related factors and metrics; and (2) empirical properties, and conditions for their application, interpretation, and validation of specific measures of usability. The second issue is crucial because it concerns the translation of numerical results — in this case scores on specific metrics — into results that are actually helpful for developers, quality assurance managers, and usability engineers. These results should inform decisions about whether particular software products meet the particular goals of its intended users.
