Statistics in the background of large scale assessments of student achievements

In 2016, the results of two large international assessments of student achievement, TIMSS and PISA were released. Slovenia participated in both. International large scale assessments (LSA) are complex multi-annual projects based on specific methodology of data collection and reporting. We will briefly show the newest results that have attracted public attention.  Then we will present the standard statistical methodology of each steps of these studies:  designing the framework for the study, sampling of the population of students and schools, administering tests for students, collecting background data with questionnaires, modeling of student responses into achievement scores as well as procedures of analyzing the available databases. We will describe the access to the data collected in the latest studies and show the use of available statistical tools for secondary analyses that could provide new information also in other areas, not only in education.