This tutorial guides you through the basics of using LIONESS with the help of an example program of a public goods game experiment. Before we start, please take note of two things: (1) elementary programming knowledge will be very useful. If you are not comfortable with web scripting languages, you might want to play around with a PHP and HTML tutorial before you proceed. (2) In principle, you can use any text editor to view and edit scripts, but a ‘source code editor’ like Notepad++ makes them much more readable. An editor indicating line numbers of a script is essential for following this tutorial.

If you are familiar with basic web programming using PHP and HTML, you can skip this introductory tutorial and directly explore the sections Design experiments and the Example experiments. If you are not comfortable with using these languages, a closer look at some of the files of the example program will show you the building blocks of a script that interact with the LIONESS server and a participant’s browser.

We assume that you followed the steps of the the kick-starter guide . If you did, you will have a local server up and running (with a database), and a folder C:\\xampp\\htdocs\\exp containing the files of the example program of a public goods game. While going through this tutorial, it is useful to run the example program as a mock experiment in your browser. This enables you to see what various parts of the codes do, to play around with the codes and test them by acting as a participant. Make sure you have the control panel open in your browser while running this mock session! Refreshing the participant’s page after saving your edited .php files will instantly show you the effects of your changes.

At the bottom of each step of this tutorial, you will find a link to the next step. You can also navigate through this tutorial using the menu bar above.