Out-of-Device Privacy Unveiled: Designing and Validating the Out-of-Device Privacy Scale (ODPS)

This paper proposes an Out-of-Device Privacy Scale (ODPS) - a reliable, validated psychometric privacy scale that measures users’ importance of out-of-device privacy. In contrast to existing scales, ODPS is designed to capture the importance individuals attribute to protecting personal information from out-of-device threats in the physical world, which is essential when designing privacy protection mechanisms. We iteratively developed and refined ODPS in three high-level steps: item development, scale development, and scale validation, with a total of N=1378 participants. Our methodology included ensuring content validity by following various approaches to generate items. We collected insights from experts and target audiences to understand response variability. Next, we explored the underlying factor structure using multiple methods and performed dimensionality, reliability, and validity tests to finalise the scale. We discuss how ODPS can support future work predicting user behaviours and designing protection methods to mitigate privacy risks.