greed or share?

September, 2016 - November, 2016

Team Project

Research through Design

What is the current behaviour of giving in the context of using vending machines, and how can interaction design stimulate giving behaviour? To answer the question, we prototyped a vending machine, tested it in the field, and eventually got some insights.


Define 'greed' & 'share'



If someone receive something for free, is he/she going to share it with someone else, or keep it himself/herself?

To figure out the answer, we designed a vending machine that is able to give free candies to people by sending them an invitation letter and ask them to collect the gifts themselves. After receiving their gifts, they could choose to buy their friends some candies or walk away.

invitation letter1-01.png

Conceptual Model

If the user receives an email to collect a gift, he/she will show the email to the vending machine and get the candy. After that, he will choose whether to buy a gift for another person or not.

If the user doesn’t receive an email, he/she will interact with the vending machine in a way of using normal vending machines. He/she will decide whether to buy a gift for a friend/stranger in the end of the process.

Interface graph.png




The user test was perfomred in a lecture building where there was a large quantity of students. 101 invitations were dilevered while 12 groups of people went to pick up their free gifts. Their behaviour were recorded. After the test, 101 users received a questionnaire.

Sharing was more likely to occur among friends, especially when they were in groups. Strangers were more reluctant to share canies with each other. However, it was interesting to see that the negative experience of interacting with the vending machine may also prohibit people from sharing candies with other people.