Author:

Keywords:

PIRLS, reading comprehension

Abstract:

Several international large-scale assessments in education take place every 3 to 5 years. piRlS (the progress in international Reading literacy Study) takes place every 5 years. if data from only one moment are considered, it is difficult to explain differences in achievement between countries. But we can also consider data from two (or more) years and focus on changes over time within each of the participating countries. following countries over a certain period in such a longitudinal ap-proach facilitates causal inferences on the effects of characteristics of educational systems.in this study, we investigate the effects of instructional time for language and reading and of amount of professional development of teachers on reading comprehension in Grade 4. We also study the effect of changes in the average age of students. By accounting for the effects of age and schooling we come to a slightly different ranking of countries in piRlS. We use a difference-in-difference ap-proach with correlation matrices. one of our conclusions is that professional development of teach-ers has an effect on the achievement level of students.Keywords: reading comprehension, instructional time, professional development, piRlS 2006, piRlS 2016, Grade 4, age.