Experimental Design Details
This study examines the effect of peer information on a health-promoting activity using an experimental approach that spanned across 8 weeks. The experiment comprises of two stages. The first stage studies the effect of peer information on the participation rate of the 10,000 steps challenge. The second stage measures the effect of peer information on performance and the effectiveness of the challenge on physical activity level.
Recruitment was done through distribution of flyers on campus with Quick Response (QR) code. In case that someone might not know how to access the QR code, we also provided an email contact for participants to receive the link to the website. When interested students scanned the QR code using their smartphones, they were directed to a registration page with a short survey. As this study intends to promote health-promoting physical activity, the target students are the inactive students. Based on the information given in the registration survey, particularly the number of hours they engage in various forms of physical activities, we invited students that were most likely to be inactive to participate in the study. They were given a fitness tracker and were required to send us the step counts on a daily basis. Detailed instructions were given to the students upon collection of the pedometers.
We recorded all participants’ daily step counts during the first four weeks of the experiment. These inactive students were then randomised by gender and school and invited to participate in the 10,000 steps challenge with the message corresponding to their treatment groups.
We provided the students in each treatment group with a message summarising the choices of their peers (descriptive information) and the majority beliefs about what ought to be done (normative information) as we invited the students to participate in the 10,000 steps challenge. We selected a few random students from both active and inactive groups and invited them to participate in the 10,000 steps challenge to form the descriptive information. The outcome of the invitation was then provided to the students in the treatment groups as descriptive information. The normative information, what one ought to do, was formed through asking the same students the following question, “Do you think individuals who walk fewer than 7,500 steps should participate in the 10,000 steps challenge?”
The students from the control group are not provided with any peer information; they only received an invitation to the 10,000 steps challenge. Students from the two treatment groups, similar peer group and superior peer group receive both information about different peers. The similar peer group receives information about peers who are similar to them in behaviour (inactive students who walked fewer than 7,500 steps a day). The superior peer group receives information about the students who were more active physically (students who walk more than 7,500 steps a day). The students were given a link to register online after they had communicated their interest in participating. Before the 10,000 steps challenge commencement date, a reminder was delivered to the participants. The normative and descriptive information was repeated in the reminder in accordance with the treatment groups. For example, students from the similar peer group received the following message:
“The 10,000 steps challenge will commence tomorrow. It will be held from 12th September to 9th October. Please set your goal as 10,000 steps and if you used to remove the band during any training or sports event, you can keep it on from now on. In a survey session, we conducted previously, about 80% of the participants who have similar step counts as you have signed up for the 10,000 steps challenge.”
After the 10,000 steps challenge, the participants were asked their reasons in joining the 10,000 steps challenge in a survey. We further conducted a content analysis of the messages written by the participants. We employed House and Xiao’s (2011) classification coordination game to incentivize coding and recruited 23 evaluators from the student subject pool for this purpose. Evaluators were seated separately and worked independently. They first read the coding instructions explaining their task. They were also provided with a summary of the walking experiment and asked to complete a quiz to ensure that they understood the instructions. They were not given any information about the purpose of the study. Evaluators then received all the challenge participants’ messages and were asked to classify each message under at least one of the six categories: reasons related to health; weight loss; peer influence; having fun; challenge; other.