Abstract Background Eco-feedback is a common solution for changing people’s behavior to reduce resource consumption. The design of eco-feedback becomes especially important in the context where users do not pay for the resources like in the case of public toilets. As people interact with these environments for a short time, it is critical to guide people’s behavior immediately in the moment.
Methods Our research aimed to investigate the effect of the designs of eco-feedback on users’ immediate reactions to water conservation. We conducted an in-lab experiment with 40 users on 32 designs of water consumption feedback display. To develop the design stimuli, we applied four design attributes suggested from a prior study. To present the feedback designs, a real-time water feedback system named SaveDrops was developed. While participants experienced the feedback designs, the amount of water consumption was measured by the prototype system. The participants’ reflections on the experience were gathered through surveys and post-interviews.
Result The experiment revealed that the graphical representation of water consumption was significantly more effective than the numeric representation. Frequent auditory feedback was also more effective than occasional feedback. Among the design stimuli, the most effective one for immediate water conservation was revealed as: the amount of consumed water, which was interpreted in a comparative percentage for other people, represented in a bar graph, and with beeping sound.
Conclusions This paper contributes to the sustainable design fields by investigating the effects of various eco-feedback designs on users’ immediate reactions. We expect that the designs and their effects can be good references for sustainable design practices. In particular, practitioners can refer to the design guidelines when designing products for reducing resource consumption. Also, they can select a design alternative by considering the effects.