How to Nudge In Situ: Designing Lambent Devices to Deliver Information Salience in Supermarkets

There are available a number of mobile shopping aids and recommender systems, but none of which can be easily used for a weekly shop at a local supermarket. We present a minimalistic, mobile and fully functional lambent display that clips onto any shopping trolley, intended to nudge people when choosing what to buy. It provided salient information about the food-miles for various food items represented by varying lengths of LEDs on the handle and a changing emoticon showing their total miles against a social norm. When evaluated in situ, the lambent handle displays nudged people to change their behaviour compared with ordinary shopping strategies; they chose products that travelled less, particularly for those that had greater choice of high mileage. They also felt guilty when the aggregate mileage of the contents of their entire shopping trolley was below the social norm. The findings are discussed in terms of how to provide different kinds of information about products that people care about through these kinds of lightweight lambent displays. Author