Televisions"), and 10% of students had missing responses on attendance at a science club ("How often do you do these things? Attend a science club"). These two questions were chosen for comparison because they appeared in both the PISA 2015 and 2006 student questionnaires, were easy for students to answer because of the closed format, and they appeared before (televisions) and after (attend a science club) the question about career expectations. The highest missing-response rate on career expectations in 2015 was observed in Germany, where about 26% of students had missing or invalid responses, followed by Austria (23%), Iceland (22%), Canada (21 %) and Chinese Taipei (21%). In Mexico, Peru and Viet Nam, only around 3% of students had missing or invalid responses to the career-expectations question, in Korea, around 4% of students had missing or invalid responses.