  Debugging physical computing projects provides a rich context to understand
cross-disciplinary problem solving that integrates multiple domains of
computing and engineering. Yet understanding and assessing students' learning
of debugging remains a challenge, particularly in understudied areas such as
physical computing, since finding and fixing hardware and software bugs is a
deeply contextual practice. In this paper we draw on the rich history of
clinical interviews to develop and pilot "failure artifact scenarios" in order
to study changes in students' approaches to debugging and troubleshooting
electronic textiles (e-textiles). We applied this clinical interview protocol
before and after an eight-week-long e-textiles unit. We analyzed pre/post
clinical interviews from 18 students at four different schools. The analysis
revealed that students improved in identifying bugs with greater specificity,
and across domains, and in considering multiple causes for bugs. We discuss
implications for developing tools to assess students' debugging abilities
through contextualized debugging scenarios in physical computing.

Computers and Society;Human-Computer Interaction