Usability Magnitude Estimation

Magnitude estimation is a measurement method that is very useful for measuring multi-faceted constructs that do not have a physical analog (e.g., usability) and are produced from multidimensional stimuli (e.g., user interfaces). Traditional usability metrics have shown limitations in usefulness and validity. Usability magnitude estimation is an assessment method whereby participants assign usability ‘values’ to tasks, conditions, or other user interface targets according to ratio-based number assignments. The resultant ratio-scale data is appropriate for parametric statistical analysis. This method has been used successfully in a variety of usability activities at Oracle. It has proven to be efficient, sensitive, and highly effective for comparisons using usability as a differentiator.