Abstract Self-determination theory (SDT) has been widely successful in human–computer interaction (HCI). It offers ready concepts, measures, and theoretical propositions for third wave HCI topics such as user experience, fun, wellbeing, motivation, or user autonomy. Still, HCI applications of SDT have been partial, at times superficial, and disconnecting—leaving great unfulfilled potential which motivated the present special issue. In this introduction, we present SDT to interested scholars, chart its use across HCI to date, and outline six advances to move HCI toward more intentional applications of SDT. As the articles from this issue illustrate, future growth areas of SDT in HCI are in extending domain-specific models and applications, harnessing underused parts of theory, computational formalization, extending levels of analysis, facilitating design translation, and engaging in a cross-disciplinary dialogue on autonomy.

The use of fitness apps (some based on behavior change theories) is increasing. Recently a taxonomy mapped app features to the Basic Psychological Needs (BPNs) posited by the Self-Determination Theory (SDT), providing the opportunity to inform the design of fitness apps by this theory of human motivation. However, it is unknown if the user’s perceptions of such SDT-based design would support the BPNs. This is important as the SDT states that interventions supporting the BPNs produce long-term benefits. Following the taxonomy of app features based on SDT, we designed and developed Agon, an iPhone app. We deployed the app through a one-month field study involving 49 participants. The study allowed participants to use the app in their everyday lives, providing sufficient exposure for us to capture meaningful perceptions. This work contributes empirical evidence that the features included in our design correctly mapped to the Basic Psychological Needs. We discuss implications for researchers and designers targeting effective interventions.

Nowadays, thousands of popular applications are designed to help users improve their lives through behavioural adjustment (e.g., meditate more, stay hydrated). However, our understanding of how certain design features align with constructs of behavior theories remain limited. We analyze 208 apps from the Apple App Store and identified 12 design features afforded by current tools that we classified according to the Self-Determination Theory. The taxonomy reported in this paper, we argue, provides a simple tool for designers to evaluate how specific features, and combination of features, may work to motivate users towards their desired goals. Additionally, the presented taxonomy is intended to help researchers test new interventions by discussing relevant research gaps.

People do not exercise as much and as regularly as they should. To support users in adopting healthy exercise routines, app designers integrate persuasive techniques in their apps. In this study, we focus on two of these techniques, i.e., offering tangible rewards and sending motivational messages to users. Past research has demonstrated the effects of these techniques in nudging recipients to increase their physical activity levels. However, the effect of these interventions on the intrinsic motivation of the participants has not yet been studied. We conducted a 10-month study involving 208 participants; this research consisted of a 3-month baseline (pre-phase), a 4-month experiment and a 3-month follow-up (post-phase). The participants were randomly assigned to one of the following three interventions: either they receive money ((i.) through a fixed incentive or (ii.) a lottery), or (iii.) informative messages. Their daily goal was to walk 10K steps. Through their smart phones, we recorded how many steps they walked every day. These interventions had no effect on the main outcome variable (i.e., the number of steps). However, the manipulations produced a detrimental effect on the intrinsic motivation of the participants, measured through a standardized questionnaire. This negative effect extended into the follow-up period. Our study reveals that tangible rewards and motivational messages decrease the intrinsic motivation of the participants, hence their connected physical activity. In our findings, we highlight the importance of intrinsic motivation in setting up healthy exercise routines that will be carried on autonomously by the participants after the period of the intervention. Finally, we present implications for the design of persuasive apps.

We introduce T9+HUD, a text entry method designed to decrease visual distraction while driving and typing. T9+HUD combines a physical 3x4 keypad on the steering wheel with a head-up-display (HUD) for projecting output on the windshield. Previous work suggests this may be a visually less demanding way to type while driving than the popular case which requires shifts of visual attention away from the road. We present a prototype design and report first results from a controlled evaluation in a driving simulator. While driving, the T9+HUD text entry rate was equal compared to a dashboard-mounted touchscreen device, but it reduced lane deviations by 70%. Furthermore, there was no significant difference between T9+HUD and baseline driving in lane-keeping performance. T9+HUD decreased glance time off road by 64% in comparison to the touchscreen QWERTY. We conclude that the data are favorable and warrant more research on attention-reducing text input methods for driving.