In November 2018, CARPE hosted the IEA-ETS Research Institute (IERI) for a three day academy on the use of Item Response Theory (IRT) and population modelling in large-scale assessments. The academy was designed and taught by Eugenio Gonzales and Peter van Rijn from the Educational Testing Service (ETS), both of whom have substantial experience in working with large-scale assessments such as TIMSS, PIRLS and PISA. The CARPE team, along with more than 20 delegates from around the globe, attended the academy. The course covered a range of topics in assessment designs, and the use of IRT and population modelling in large-scale assessments. The CARPE team familiarised themselves with different assessment designs and IRT models, and used commercially available software to apply IRT and generate proficiency estimates. This was a great opportunity for CARPE to build upon the knowledge acquired during the professional development course with Prof. Laura O’Dwyer and Prof. Larry Ludlow from Boston College last summer.