Instrument validation and factor analysis for defining the quality of education for sustainable development in higher education

Education for Sustainable Development (ESD) is increasingly emphasised in higher education; however, empirically grounded models to guide its implementation remain limited. This study aimed to validate the underlying structure of an instrument as an intermediate step toward developing a model for ESD implementation in higher education institutions (HEIs). A sequential mixed-methods design was employed, with this paper focusing on the quantitative validation phase. An initial pool of 105 items was developed from prior qualitative findings and subsequently refined through expert validation using the Item Content Validity Index (I-CVI) and Scale Content Validity Index (S-CVI). Exploratory Factor Analysis (EFA) was conducted using data collected from 100 academic staff across 20 public universities in Malaysia to examine the underlying factor structure and refine the instrument. To further investigate the internal composition of each factor, a second-stage Principal Component Analysis (PCA) was subsequently performed. The results supported a four-factor structure representing key dimensions of ESD implementation: (i) Systemic ESD Curriculum Content and Pedagogy, (ii) Adaptive ESD Curriculum Structure and Pathways, (iii) Sustainability Competencies Outcomes, and (iv) Integrated Assessment of ESD Learning. The PCA results further revealed meaningful subdimensions within each factor, with the first dimension comprising five subdimensions and the remaining dimensions comprising two subdimensions each. The findings highlight a multidimensional approach to ESD implementation that differs from conventional curriculum models by explicitly specifying the quality of curriculum required to effectively integrate sustainability. Rather than focusing solely on structural components, the proposed model emphasises the characteristics of effective ESD, including the integration of content, pedagogy, assessment, and outcomes to ensure meaningful and context-relevant learning. Overall, this study provides an empirically grounded framework for ESD implementation in higher education institutions (HEIs), offering practical insights into the quality of curriculum design required to effectively integrate sustainability. The findings inform curriculum development and institutional strategies by highlighting key dimensions that support meaningful and context-relevant ESD. Further validation using confirmatory techniques is recommended to strengthen the proposed model. Not applicable.