LIONESS experiments regulate the information flow between participants. Before a session, the experimenter uploads the LIONESS experiment to the server. In a typical online experiment participants log in to the server via a link posted on a crowd-sourcing website (e.g. Amazon Mechanical Turk). Participants interact through their web browsers and receive a code to collect their payment upon completion. Throughout the session, the control panel displays the participants’ progress in the experiment.
The control panel allows the experimenter to control the experimental flow (start and stop the experiment), observe the data collection and download the data and payment file. The control panel also triggers the central controller algorithm. During a session, the control panel needs to be open on the experimenter's computer at all times.
LIONESS experiments provide a set of standarized methods for group formation, attrition and other challenges of interactive online experiments. This is extensively discussed in a this paper by Arechar et al.