The Programme for International Student Assessment (PISA) introduced creative thinking as an innovative domain in 2022. This paper examines the unique methodological issues in international assessments and the implications of measuring creative thinking within PISA's framework, including stratified sampling, rotated form designs, and a distinct scoring metric. Cross-cultural considerations and data quality issues underscore the need for critical evaluation of cultural equivalence and data quality, especially at the individual educational system level. The paper also highlights the limitations of causal inference and provides guidance and resources for handling sampling weights, plausible values, and multilevel structures. By reflecting on PISA's history and design, this work offers insights for researchers navigating the complexities of innovative domain assessment to ensure valid interpretations.