Testing Concerns about Technology's Behavioral Impacts with N-of-one Trials.

As public trust in technology companies has declined, people are questioning the effects of digital technologies in their lives. In this context, many evidence-free claims from corporations and tech critics are widely circulated. How can members of the public make evidence-based decisions about digital technology in their lives? In clinical fields, N -of-one trials enable participant-investigators to make personalized causal discoveries about managing health, improving fitness, and improving their education. Similar methods could help community scientists understand and manage how they use digital technologies. In this paper, we introduce Conjecture, a system for coordinating N -of-one trials that can guide personal decisions about technology use and contribute to science. We describe N -of-one trials as a design challenge and present the design of the Conjecture system. We evaluate the system with a field experiment that tests folk theories about the influence of colorful screens on alleged phone addiction. We present findings on the design of N -of-one-trial systems based on submitted data, interviews, and surveys with 14 participants. Taken together, this paper introduces N -of-one trials as a fruitful direction for computer scientists designing industry-independent systems for evidence-based technology governance and accountability.