Psychometric validation of the eComplexity instrument in international postgraduate education: evidence from a multicultural Japanese context

Purpose This study validates the psychometric structure of the eComplexity instrument in a large sample of international postgraduate students at a Japanese university. It examines the hierarchical configuration of complex thinking and the relative contribution of its general and specific factors in multicultural postgraduate contexts. Design/methodology/approach A quantitative multimethod design was applied to data from 491 international master's students. Analyses included EBICglasso network estimation, confirmatory factor analysis with WLSMV, bifactor and hierarchical models and advanced reliability indices (ω_total, ω_hierarchical, ECV). Convergent and discriminant validity were assessed using CR, AVE and Fornell–Larcker criteria. The instrument was administered in English, Japanese and Chinese following translation/back-translation procedures. Findings A strong general factor was identified (ω_total = 0.958; ω_hierarchical = 0.803; ECV = 0.71), indicating that most reliable variance reflects a unified competence. Subscales showed high total but low specific reliability, functioning as dependent facets rather than autonomous domains. Network and CFA results support a multidimensional yet hierarchical structure. Although discriminant validity was not confirmed, consistent with highly integrated constructs, the instrument demonstrates strong structural and convergent validity in a multicultural postgraduate sample. Research limitations/implications Data were drawn from a single technological institution and relied on a cross-sectional self-report design, limiting generalizability and developmental inference. Future research should incorporate longitudinal, cross-institutional and performance-based approaches. Practical implications Results support using a global complex thinking score for diagnostic and curricular purposes in international postgraduate programs, while subscales inform targeted interventions. Originality/value This is the first validation of eComplexity in a multicultural Japanese postgraduate population, strengthening its theoretical and empirical foundations as a hierarchical measure of complex thinking in advanced education.