The API walkthrough method: a lightweight method for getting early feedback about an API

We propose a method for evaluating the usability of an Application Programming Interface (API) in the context of MATLAB, a high-level programming language. The primary goal is to evaluate whether the participant can develop an accurate mental model of the API based on the code alone. Like traditional usability testing, this method takes place in a lab setting with a facilitator and observers, and a single participant is exposed to a prototype. Unlike traditional usability testing, the prototype is a static text document containing a series of programmatic statements. Rather than performing a task, the participant "walks through" the code line by line in an attempt to gain understanding of the system. Using standard usability testing protocols, the facilitators are able to assess whether the participant understands the API, as well as gather preference data between two designs.