Bridging knowledge and practice: a validated scale for sustainability literacy in higher education

Sustainability education requires learners to develop knowledge, values, competencies and action-oriented behaviors, yet existing instruments capture only parts of this construct knowledge in the Sulitest and Assessment of Sustainability Knowledge; consciousness and attitudes in the Sustainability Consciousness Questionnaire and Attitudes toward Sustainable Development scale, rely largely on school-age or Western samples, and offer limited confirmatory evidence of their structure. To fill this gap, this study developed and validated the four-dimensional St Aloysius- Sustainability Literacy Scale (SA-SLS) instrument, capturing Cognitive Sustainability Literacy, Ethical and Value Orientation, Transformative Competencies, and Sustainability Engagement and Action. The scale development consisted of a rigorous series of literature-based item generation, expert review and pre-testing, as well as an Exploratory Factor Analysis (EFA) on one random subsample followed by Confirmatory Factor Analysis (CFA) on an independent subsample of 1,068 university students. A robust four-factor structure was confirmed. Factor loadings of items ranged from 0.74 to 0.885. Internal consistency was good for all constructs, with Cronbach's alpha and Composite Reliability (CR) above 0.70 (CR = 0.846–0.884). Convergent validity was confirmed using Average Variance Extracted (AVE = 0.563–0.602), discriminant validity was confirmed using the Fornell–Larcker criterion, with maximum shared variance being lower than AVE for all constructs. Content validity was also confirmed, with Aiken's V coefficients above 0.70 for representativeness, importance, and clarity for all 41 items. The fit of the model indices were adequate or above recommended values (χ 2 /df = 2.236, RMSEA = 0.042, SRMR = 0.048, CFI = 0.977, TLI = 0.967, NFI = 0.948, GFI = 0.922, AGFI = 0.923). These results support a multidimensional, four-factor conceptualization of sustainability literacy comprising knowledge, values, competencies, and action, extending prior single- or partial-dimension instruments by operationalizing these four dimensions within one validated measurement model. To summarize, these findings suggest that the SA-SLS offers a psychometrically sound advance in operationalizing sustainability literacy as a multidimensional construct, providing higher education institutions with a tool to assess and benchmark sustainability literacy for curriculum design and SDG-aligned policy, with future work needed to validate it across multiple institutions and cultural contexts to establish broader generalizability.