Nudging behaviors through user interface design is a practice that is well-studied in HCI research. Corporations often use this knowledge to modify online interfaces to influence user information disclosure. In this paper, we experimentally test the impact of a norm-shaping design patterns on information divulging behavior. We show that (1) a set of images, biased toward more revealing figures, change subjects' personal views of appropriate information to share; (2) that shifts in perceptions significantly increases the probability that a subject divulges personal information; and (3) that these shift also increases the probability that the subject advises others to do so. Our main contribution is empirically identifying a key mechanism by which norm-shaping designs can change beliefs and subsequent disclosure behaviors.

Walking and other forms of physical activity have many health benefits, but people often fail to follow through on their own goals of being more active. To address gaps in current understanding of how to design technology-supported physical activity interventions, we conducted a randomized field experiment of a commitment device: making public announcements. In a control condition, weekly commitments were kept private. In two treatment conditions, they were announced on Facebook and by email. In one of the two, the announcements also included results: whether the previous week's commitment was kept. We find that, with or without public results, these posts can elicit supportive replies from the poster's social networks. People in both public announcements conditions were less likely to make commitments. We conclude that the prospect of public accountability may suppress the making of commitments in a way that counteracts the benefits of that accountability. Designers will need to address this limitation in order to make effective use of public accountability as a commitment device.