Bonn eXperimental System (BoXS): An open-source platform for interactive experiments in psychology and economics.

The increased interest in complex-interactive behavior on the one hand and the cognitive and affective processes underlying behavior on the other are a challenge for researchers in psychology and behavioral economics. Research often necessitates that participants strategically interact with each other in dyads or groups. At the same time, to investigate the underlying cognitive and affective processes in a fine-grained manner, not only choices but also other variables such as decision time, information search, and pupil dilation should be recorded. The Bonn eXperimental System (BoXS) introduced in this article is an open-source platform that allows interactive as well as non-interactive experiments to be conducted while recording process measures very efficiently and completely browser-based. In the current version, BoXS has particularly been extended to enable conducting interactive eye-tracking and mouse-tracking experiments. One core advantage of BoXS is its simplicity. Using BoXS does not require prior installation for both experimenters and participants, which allows for running studies outside the laboratory and over the internet. Learning to program for BoXS is easy even for researchers without previous programming experience.