Four amazing oTree apps

The online community of oTree has useful, ready-made apps available for those looking to conduct run experiments, laboratory studies, field studies, and surveys. In this post, I highlight a few apps that may be useful for accounting researchers.

Bomb Risk Elicitation Task (BRET)

Bomb Risk Elicitation Task The Bomb Risk Elicitation Task (BRET) is an improved elicitation procedure for risk preferences by Crossetto and Filipin (2013) that uses a bomb. Felix Holzmeister designed an oTree app for the BRET. In its most basic form, participants view a matrix with boxes. After pressing “Start,” the computer collects one box per second. Once collected, a participant earns a fixed amount of money. However, behind one of the boxes in the matrix hides a bomb that destroys everything that has been collected, but participants do not know where the bomb is located. The main task participants face is choosing when to stop collecting boxes. If participants stop collecting boxes, they earn the money they collected so far. However, if they collect the box with the bomb behind it, they will earn nothing. You can test the BRET here, and download the code here. The oTree app for BRET also uses other forms to elicit risk preferences. In another form, participants directly enter the number of boxes they wish to collect rather than wait for the computer to collect boxes. In sum, the oTree app for BRET is an engaging and natural way to elicit participants’ risk preferences. Felix Holzmeister shares numerous other oTree apps on his website for eliciting risk using other established procedures.

Real Effort Tasks

Real Effort Task Real Effort Task Curtis Kephart created two oTree apps for real effort tasks. In one task, players must correctly type as many character strings as possible within a certain time limit (see the gif above). Another task instructs participants to add as many integers as possible within a timelimit correctly. The code can be downloaded here.

Slider Task

Slider Some experiments in management accounting have started using the slider task (e.g., Chan, 2018; Choi et al., 2018). The slider task, originally introduced by Gill and Prowse (2012), shows participants a screen with 48 sliders, where each slider ranges from 0 to 100. Sliders are solved by moving the slider's marker (initially placed at 0) to the midpoint of 50. Participants are given 2 minutes to solve as many sliders as possible, with the participant's chosen effort given by the number of sliders correctly positioned at 50 by the end of the two minutes. Participants normally repeat the task 10 times and earn their accumulated earnings. Christian König has developed an oTree app for the slider task. The code is available here.

Social Value Orientation

Real Effort Task Another measure used in accounting studies is Social Value Orientation (Murphy, Ackermann, and Handgraaf, 2011). It measures prosociality, categorizing participants into one of four categories (Individualistic, Competitive, Prosocial, and Altruistic). An active contributor to the oTree community, Philipp Chapkovski has developed an oTree app that measures participants’ Social Value Orientation. The code and documentation is available here

How to reference this online article?

Van Pelt, V. F. J. (2019, November 23). Four amazing oTree apps. Accounting Experiments, Available at:

Victor van Pelt
Assistant Professor of Management Accounting