SEA-PLM 2024 employed rigorous technical procedures to transform student responses into reliable and comparable measures of learning achievement in reading, writing, and mathematics. These procedures included the coding of constructed-response items, the scoring of assessment responses, and the application of psychometric scaling methodologies to estimate student proficiency levels. This report outlines the coding frameworks, quality control processes, scoring approaches, and scaling methodologies used to ensure valid, reliable, and internationally comparable reporting of learning outcomes across participating countries.