Measurable Concepts for the Usability of Software Components

While usability has proven to be an important software quality attribute, its application to APIs is still rather uncommon. Available methods for measuring software usability show significant disadvantages when applied to APIs, like the need for test users and experienced evaluators. This makes it difficult to evaluate the usability of software components, as well as to compare different software components. An API usability measurement method is needed that is both machine-computable and objective. This paper takes a first step in the direction of such a measure by identifying measurable concepts for the usability of software components, and validating these concepts against existing studies and guidelines for usability and API design.