Behavioral pre-testing of COVID Tracker, Ireland’s contact-tracing app

Contact-tracing mobile phone apps can play a role in controlling the spread of COVID-19, but their success hinges on widespread public acceptance, uptake and use, which are difficult for public administrators to foresee. We report on a rapid behavioral pre-test of COVID Tracker, Ireland’s contact-tracing app, prior to its launch. A large sample of participants were randomized to receive different versions of a trial app. They responded to an online survey while downloading and using the app on their phones in real time. Experimental manipulations focused on: (i) the level of privacy assurance provided in the app, (ii) the goal-framing of the purpose of the app and (iii) the structuring of the exposure notification. Almost one in five participants mentioned privacy concerns in relation to their likelihood of downloading the app, but concerns were lower and engagement stronger in a condition that included additional assurances regarding the privacy of users’ data in the app. This finding informed the final version of the app. Overall, our results demonstrate the value and feasibility of pre-testing digital interfaces to improve public administration.