Security developer studies with github users: exploring a convenience sample

The usable security community is increasingly considering how to improve security decision-making not only for end users, but also for information technology professionals, including system administrators and software developers. Recruiting these professionals for user studies can prove challenging, as, relative to end users more generally, they are limited in numbers, geographically concentrated, and accustomed to higher compensation. One potential approach is to recruit active GitHub users, who are (in some ways) conveniently available for online studies. However, it is not well understood how GitHub users perform when working on security-related tasks. As a first step in addressing this question, we conducted an experiment in which we recruited 307 active GitHub users to each complete the same security-relevant programming tasks. We compared the results in terms of functional correctness as well as security, finding differences in performance for both security and functionality related to the participant's self-reported years of experience, but no statistically significant differences related to the participant's self-reported status as a student, status as a professional developer, or security background. These results provide initial evidence for how to think about validity when recruiting convenience samples as substitutes for professional developers in security developer studies.