The conventional assumption that quality is an attribute of a product is misleading, as the attributes required for quality will depend on how the product is used. Quality of use is therefore defined as the extent to which a product satisfies stated and implied needs when used under stated conditions. Quality of use can be used to measure usability as the extent to which specified goals can be achieved with effectiveness, efficiency and satisfaction by specified users carrying out specified tasks in specified environments. Practical and reliable methods of measuring quality of use have been developed by the MUSiC project. These provide criteria for usability which can be incorporated into a quality system. A description is given of the MUSiC methods for specifying the context of use and measuring effectiveness, efficiency, and satisfaction.
['Nigel Bevan']
Measuring usability as quality of use