Developments in International Masterclasses

International Masterclasses are events for high school students that enable them to act as "particle physicists for day" by analyzing authentic data from particle physics experiments under the tutelage of scientists. International Masterclasses have been very successful and have grown with their focus on data from the Large Hadron Collider at CERN. Recent developments that bring masterclasses to more students in more ways have been very exciting. The number of masterclasses and the number of countries with masterclasses have grown substantially. Outreach efforts such as masterclass workshops in developing countries, particularly in collaboration with the African School of Fundamental Physics and Applications, and a new International Day of Girls and Women in Science masterclass have yielded success. Most recently, there are new initiatives to expand masterclasses beyond the LHC, particularly into neutrino physics.