Experimental Design Details
The study runs online on the Prolific platform. The experiment automatically redirects participants between parts that run on the survey platform Qualtrics and game modules that run as a WebGL app within the browser. At the end of each part of the study, participants are redirected to the Prolific platform to automatically register the completion code.
Date 1 (Part 1). After reading and accepting the consent form, subjects enter game module 1. It starts with a short video introducing the game mechanics. Subjects then play a practice round of the game without time pressure and subsequently complete two recipes under time pressure (a timer appears in the game screen, but the game continues after the 5-minute time limit elapses).
After this module, subjects complete a survey and then receive information about safe food handling in the form of a 2-minute video. The survey consists of questions about food safety related knowledge and behavior targeted by the game. Further, we ask about individual characteristics such as age, household type, risk preferences in general and specific to the food safety domain, food and cooking preferences. The information in the video addresses the following four broad categories: Personal hygiene (such as hand washing), kitchen hygiene (such as cleaning utensils and surfaces), rinsing fresh vegetables and fruits, and handling meat (to not rinse meat; to check with a food thermometer that meat is thoroughly cooked).
Subjects continue with game module 2. It starts with a video showing a play-through of the game that explains correct behavior in the light of the food safety advice that they just received in the video at the end of the survey module. Subjects then play through four recipes to give us data on their behavior after they have received the food safety advice. Subjects do not get any feedback about their performance in the game and do not know yet on what feedback will be given in the remainder of the study.
Subjects then continue with game module 3, which is the stage were the experimental variation of the study happens. Subjects are randomly assigned to one of the three experimental conditions (Control, Reminder, and ManyReminders), stratified by gender to achieve balance across conditions. In all three conditions, subjects are first told that their payment from now on will depend on how well they play the game: Next to the fixed payment (GBP 8 for part 1 and GBP 6 for part 2) there is a bonus of up to GBP 3 based on how well a subject plays the game from now on. Specifically, one of the five game levels that a subject will subsequently play through in the remainder of date 1 and on date 2 will randomly be drawn at the end of the study. The bonus is then calculated as GBP 3 x (percentage score) of the level drawn, where the percentage score assigns a value between 0 and 1 based on how many of the four recipes in the level were completed within the time limit and how many of the important food safety actions (IFSAs) were correctly performed. A brief video at the start of game module 3 explains to the subjects how the score is determined and what feedback they receive at the end of each level about their performance. Subjects then play through the three levels of game module 3. Each level requires completing four recipes.
Date 2 (Part 2). 48 hours after part 1 was opened up on the Prolific platform, part 2 is opened up for those subjects who completed part 1. Here subjects complete game module 4, which is identical across all treatments. Subjects play the game and receive feedback after each of two levels (each level consists of four recipes). That is, the reminders are withdrawn for the Reminder and ManyReminder treatments. After game play, subjects answer a few questions about enjoyment of the game, possible information seeking regarding food safety during the time of the experiment, and they can enter comments about the study before registering their completion of the study.
Subjects do not get any feedback on their performance in the game (instead of getting feedback on their performance at the end of each level in modules 3 and 4). Information in the videos is adjusted accordingly.