Empirical Validation of a Skills-Based Curriculum Model in Lower Secondary Schools in Tehran: Factor Analysis and Model Fit Assessment

Abstract

This study aimed to empirically validate a skills-based curriculum model for lower secondary schools in Tehran by examining its factor structure and assessing the fit of the proposed model to empirical data. This applied study employed an exploratory sequential mixed-methods design. In the qualitative phase, an emergent grounded theory approach was used to identify and organize the components of a skills-based curriculum through a review of scientific sources and semi-structured interviews with 15 experts selected purposively and through snowball sampling until theoretical saturation. In the quantitative phase, the population consisted of lower secondary school principals in Tehran, and multistage cluster sampling was applied. Of 350 distributed questionnaires, 325 usable responses were analyzed. Data were collected using a researcher-developed 35-item questionnaire covering seven dimensions. Face and content validity and preliminary construct validity were examined, while reliability was assessed using Cronbach’s alpha. Exploratory factor analysis was performed using principal axis factoring with Promax rotation, and model fit was evaluated using SRMR, d_ULS, d_G, chi-square, and NFI indices. The Kaiser–Meyer–Olkin index was 0.957, and Bartlett’s test of sphericity was significant (χ²=6845.327, df=595, p<0.001), confirming the suitability of the data for factor analysis. Exploratory factor analysis extracted seven factors that jointly explained 65.166% of the common variance, with satisfactory primary factor loadings. Model-fit assessment yielded SRMR=0.063, d_ULS=2.257, d_G=2.483, χ²=1676.088, and NFI=0.860, indicating acceptable fit between the proposed structure and the empirical data. One-sample t-tests further showed that respondents rated the principal model dimensions significantly above the reference value of 3.5 (p<0.001), supporting their empirical acceptability. The findings support the empirical validity of the seven-factor structure of the skills-based curriculum model. Curriculum objectives, curriculum content, teaching–learning strategies, teacher role, learner role, learning assessment, and learning environment demonstrated satisfactory factorial coherence and acceptable overall model fit. The proposed model can therefore serve as an empirically supported framework for designing, evaluating, and developing skills-based curricula in lower secondary education.