Every year, ForskarFredag arranges a citizen research project that involves the public, often with a focus on school students. In these mass experiments, the public helps researchers collect more and a different type of data than they could have managed on their own. The projects also create valuable contacts between researchers and the public, give the participants insight into scientific method and contribute to an understanding of how research works. The non-profit association Vetenskap & Allmänhet coordinates the mass experiments as part of the annual science festival ForskarFredag. Schools and the public all over Sweden are invited to participate. We are now looking for researchers who want to collaborate for the coming year. Email massexperiment@forskarfredag.se no later than June 8, 2023.