An Effort Based Model of Software Usability

This paper presents a new effort based model for software usability and reports the results of a set of experiments performed to assess the validity of the model. The model is based on the notion that usability is an inverse function of effort. Physical and mental effort are obtained and inferred from logging physical activity and eye tracking. Using the new model, an objective metric of software usability that facilitates setting measurable requirements and enables the comparison of two or more implementations of the same application is developed. The experiments results show high correlation to learning theory models, strongly support the relationship of effort to usability and demonstrate that operability, learnability, and understandability of software systems can be measured using the effort based metric .