A Pilot Study of the Safety and Usability of the Obsidian Blockchain Programming Language

Abstract

Although blockchains have been proposed for building systems that execute critical transactions, security vulnerabilities have plagued programs that are deployed on blockchain systems. The programming language Obsidian was developed with the purpose of statically preventing some of the more common of these security risks, specifically the loss of resources and improper manipulation of objects. The question then is whether Obsidian’s novel features impact the usability of the language. In this paper, we begin to evaluate Obsidian with respect to usability, and develop materials for a quantitative user study through a sequence of pilot studies. Specifically, our goal was to assess a) potential usability problems of Obsidian, b) the effectiveness of a tutorial for participants to learn the language, and c) the design of programming tasks to evaluate performance using the language. Our preliminary results tentatively suggest that the complexity of Obsidian’s features do not hinder usability, although these results will be validated in the quantitative study. We also observed the following factors as being important in a given programmer’s ability to learn Obsidian: a) integrating very frequent opportunities for practice of the material – e.g., after less than a page of material at a time, and b) previous programming experience and self-efficacy. 2012 ACM Subject Classification Software and its engineering → Domain specific languages; Humancentered computing → User studies; Human-centered computing → Usability testing