There are situations where it would be desirable to manipulate the subjective time, and many studies have proposed methods to manipulate the subjective time for purposes such as reducing waiting time. However, it isn't easy to use previous methods in various situations because most of them use visual and auditory information. This study proposes a method to manipulate the subjective time by tactile stimuli of wrist-worn devices. Since wrist-worn devices such as smartwatches are widely used and can present tactile stimuli at any time, our method can be used without blocking visual or auditory perception channels. We designed tactile stimuli presentation methods that change the number of stimuli. The evaluation result clarified the elements of tactile stimuli that intentionally changed the subjective time and confirmed that our method could change the subjective time by about 21% (from -3% to 18%). Since few studies focused on the phenomenon that the subjective time changes depending on tactile stimuli of information devices, our study can contribute to designing information devices and user experiences. CCS CONCEPTS• Human-centered computing → Human computer interaction (HCI).

Although it is socially and ethically important not to be late for a specified arrival time, late arrivals sometimes happen to people using public transportation. Although many methods aim to smooth a user's movement by providing useful information, there are few approaches to prevent late arrivals due to psychological factors. In this research, to make a user's arrival time earlier and thus prevent late arrival, we propose a method that manipulates time allowance by presenting information based on a psychological and cognitive tendency. We apply this method to a vehicle timetable system for the purpose of preventing public transit users from arriving after a target vehicle's departure time. Our proposed timetable system manipulates the time intervals between a user's target vehicle and other vehicles by introducing fictional elements such as hidden vehicles and inserted fictional vehicles. This method uses the relationship between the time allowance and the departure time interval, and it can make a user desire and accept arriving at a station earlier. We implemented a prototype system and conducted four experiments. The evaluation results confirmed that our proposed method is effective for changing a user's time allowance and actual arrival time.

No abstract

No abstract

Systems presenting information that encourages competition by using rankings and scores (hereafter referred to as competition information) have become widespread to support behavioral change. However, users without high levels of motivation, such as behavior change support targets, do not necessarily benefit from competition information. In this study, we propose a method to control the psychological effects caused by competition information to support behavior change. We implemented a competition information presentation system using step counts logs to support increasing one’s daily steps. We designed two patterns of competition information considering psychological effects. One is likely to have good effects, using three mechanisms to easily obtain results corresponding to the effort, make closely matched rivals with similar abilities, and pay attention to a small number of rivals. The other is unlikely to have positive effects and may potentially even have negative ones, using a mechanism that brings about the opposite results of the former pattern. We evaluated 42 participants with low levels of motivation over six weeks. The results showed that the former information pattern increased participants’ step counts by about 1000 steps per day, and the latter information pattern did not lead to an increase. We confirmed the feasibility of the proposed method and discussed the possibility of the appropriate use and potential abuse of such techniques for manipulating motivation. Our study can be helpful in designing a competition information presentation system considering psychological effects.