Evaluating academic motivation among Chinese secondary EFL learners: validation and measurement invariance.

Inspired by self-determination theory (SDT), the Academic Motivation Scale (AMS) was developed to measure students' learning motivation. While the AMS has been widely validated and used in educational contexts, it has generally overlooked the domain-specific nature of academic motivation, particularly in learning English as a foreign language (EFL) in China, home to the world's largest population of EFL learners. This study sought to adapt the AMS and substantiate its validity using both within-network and between-network approaches with a sample of 1,390 Chinese secondary EFL learners. Results from item analysis, internal consistency, and confirmatory factor analysis (CFA) showed that the 28-item EFL-specific AMS exhibits robust psychometric properties, characterised by a seven-factor structure, and demonstrates invariance across gender and grade levels. Structural equation modelling (SEM) analyses further indicated that both extrinsic and intrinsic motivations are positively correlated with perceived teacher support, engagement, and achievement, whereas amotivation is inversely associated with these outcomes. Implications, limitations, and directions for future research are also discussed.