Abstract
Abstract In mathematics teacher education, limited empirical evidence is available on how technology-enhanced Design Thinking (DT) training supports teachers’ instructional design competencies, and even fewer studies have examined the psychometric quality of performance-based criteria used to evaluate such training processes. This study aims to examine two complementary issues: first, the effect of technology-enhanced DT training on mathematics teachers’ DT competencies, and second, the validity and reliability of the evaluation criteria developed for the training process using the Many-Facet Rasch Measurement (MFRM). The study was conducted with 18 mathematics teachers using a single-group pretest–posttest design. Data were collected through a multidimensional DT skills scale and a training evaluation rubric, and were analyzed using paired-samples t-tests, content validity indices, and MFRM. The results showed a significant increase in teachers’ total DT scores from pretest to posttest, t(17) = 2.97, p = .01, with a moderate-to-large effect size, dz = 0.70. MFRM analysis demonstrated acceptable model–data fit, with high rater separation reliability (0.86) and moderate criterion separation reliability (0.62), while also revealing meaningful differences in rater severity and criterion difficulty. The findings suggest that technology-enhanced DT training can support mathematics teachers’ instructional design competencies; however, the results should be interpreted as preliminary due to the small sample size, single-group design, and absence of follow-up data.