Dear Participant,

We are researchers investigating ways to make code review more efficient. We would be grateful if you could help our research and participate in our experiment on this subject. In this experiment, we will ask you to review some code changes in Java, specifically looking for defects in the code. Additionally, we will ask you about your experience in software development and optionally measure certain aspects of your memory capacity.

With this experiment:

• we compare the performance of code review under different circumstances
• your data will only be stored and used in anonymized form
• you will be done in about one or two hours
• you can compare your results to others after the analysis
• you will get the chance to win one of three EUR 200 (~ USD 230) cash prizes*

The commits to review are based on a Java project, so basic Java skills are needed.

Please stay focused on the experiment until it ends, otherwise we won't be able to use your data. If you have to interrupt the experiment for some reason during the reviews, please use the "pause" button that will appear in the upper right corner during the review tasks. Please don't interrupt for hours or even days, and please don't restart once you started reviewing.

It would be great if you could put your browser into full-screen mode now. Often this can be done by pressing F11.

By pressing "Start", you agree that we can use your anonymized data from this study for our research.

Thank you and we really hope you enjoy participating in our study!

Tobias** and Alberto***

**Tobias Baum, Ph.D. Student at Leibniz Universität Hannover
***Alberto Bacchelli, SNF Professor at University of Zurich

*some more details on the cash prize: Among the better half of participants in terms of average review efficiency (= defects found per hour), three participants will be selected by chance to win EUR 200 each. We expect far less than 100 participants, so chances of winning are quite good. Participants that take part multiple times or otherwise try to fake results will be excluded from the lottery. Decisions are final.

Please contact tobias.baum@inf.uni-hannover.de in case you encounter any problems with the experiment.