Indicators that directly measure the skills of individuals are therefore needed. For this purpose, an indicator of reading skills of 15-year-old students is used here. This indicator captures reading literacy, defined as the “understanding, using, reflecting on and engaging with written tests, in order to achieve one’s goals, to develop one’s knowledge and potential, and to participate in society” (OECD, 2010c). The 2009 wave of PISA tested 470 000 students, representing 26 million 15-year-olds in the schools of the 65 participating countries.