Good day,
thank you for taking part in the Crowd Estimation Study.
You will be shown 15 images of groups of varying sizes, from a few people to massive crowds.
Participation will take no more than 6 minutes.

We strongly recommend using a computer or tablet. On a small smartphone screen, the figures may blur together even in medium-sized groups.
If possible, hide your browser controls by pressing the F11 key. This will reduce distractions and free up more space on the screen.

Before you proceed, please review the following conditions:
1.  Your participation is completely anonymous. We are committed to the highest standards of data protection — we will not collect or store any personal data (not even your age or gender). You will only be asked about your country of residence, as the study is designed to be international.
2.  Participation in the study is entirely voluntary, and you may end it at any time.
3.  By clicking the “I Agree” button below, you provide informed consent for your anonymous responses to be included in our study.

If you have any questions or comments about the study or your participation, feel free to contact us:

Petr Tureček, Faculty of Science, Charles University
petr.turecek@natur.cuni.cz

Thank you for your time!