This report draws on data collected as part of the 2015 cycle of TIMSS (Trends in International Mathematics and Science Study), one of the largest and most in-depth studies of educational achievement in the world. TIMSS is designed to assess the mathematics and science skills of students in Fourth grade (equivalent to Fourth Class in Ireland) and Eighth grade (Second Year) in participating countries. Ireland was one of the 56 countries and seven benchmark participants that took part in the 2015 cycle of TIMSS.