International Masterclasses is a program that enables high school students worldwide to
experience particle physics data analysis up close. We explore what masterclasses are, how they
work, and their reach. We also look at the masterclass measurements for the four major LHC
detector experiments as well as other masterclasses and masterclass-related opportunities.
Finally, we take a look at how a masterclass is done with a very short, very simplified LHC
dimuon demonstration measurement. This work is presented on behalf of the International
Particle Physics Outreach Group.

