Z-Tree Unleashed: A Novel Client-Integrating Architecture for Conducting Z-Tree Experiments Over the Internet

Abstract

We present z-Tree unleashed, a novel approach and set of scripts to aid the implementation of experimental economics laboratory experiments outside of the laboratory. z-Tree unleashed enables subjects to join the experiment using a web portal that requires no additional software. Experimenters are likewise enabled to administer their experiments from anywhere in the world. Except for the experimental software itself, z-Tree unleashed is entirely based on free and open source software. In this paper, we firstly outline the motivation. Secondly, we give a high-level overview of z-Tree unleashed’s advantages and its design. We then proceed to show how to set up the server and demonstrate the steps required for conducting an entire experiment. We subsequently explain how to leverage the security and routing features of a virtual private network with z-Tree unleashed, enabling servers to securely run behind routers.