International comparative studies like PISA are becoming increasingly important in the development of evidence-based education policy. The potentially far-reaching influence of the outcomes of state, national and international assessments underscores the need for the results to be valid and reliable. Within the education community there is increasing recognition of the impact of motivational factors on student learning and test-taking. Is there evidence of positive motivation when students participate in large-scale reading assessments? This book investigates possible threats to the validity of reading proficiency assessments by examining two motivational variables: the interest generated by texts students read, and the amount of effort that student invest in undertaking these assessments. Drawing on multi-grade and cross-national samples, findings reveal that the majority of students are cognitively and emotionally engaged participants in large-scale studies. The findings should be useful to policy makers, test administrators and educational researchers seeking to maximise student interest and effort in large-scale assessment.