Especially in reading literacy, students were below the average of the Organisation for Economic Cooperation and Development member states.

Janez Vogrinc, Dean of the Faculty of Education at the University of Ljubljana, says: ''Our textbooks, especially the workbooks, will need to be thoroughly considered. The workbooks that seem to be the most successful right now sale-wise are the ones, which are likeable.’’

Igor Saksida, a professor at the Faculty of Education in Ljubljana, adds: ''We must not think only of those who cannot do a lot, but we must also think of those who can do more. It will be necessary to move away from the paradigm that a friendly school is a playful and easy school. The only kind and fair school, and the best countries know this, is a demanding school.''

The committee called on the Education Ministry to take measures to address the issue.

In the mentioned survey, 15-year-olds also achieved above-average results in mathematical and scientific literacy.