More information, and the registration form can be found here:
https://indico.cern.ch/event/1070335/
In this event, participants get an introduction to the Masterclasses program and can try out data measurements from various experiments. These Masterclass measurements are primarily intended for groups of high school students in International Masterclasses, a program of the International Particle Physics Outreach Group (IPPOG). More than 220 universities and research labs in 60 countries worldwide participate in the program, and graduate students are usually involved as tutors.
Learning groups are guided by Masterclass experts. A short introduction is followed by two successive 45-minute sessions; participants can come to one or both.