Andi Harpeni Dewantara, Bambang Sri Anggoro, Sari Saraswati, H.S. Rahmat
Ensuring that teachers possess a strong understanding of mathematical literacy is crucial for effective classroom instruction. This study aims to develop a valid and realiable instrument to measure teachers' understanding about mathematical literacy. This research involved five experts as instrument validators and 296 Indonesian mathematics teachers. This study was employed in two main stages: constructing TUML scale and assessing its feasibility including proving content validity through expert judgment, proving construct validity using Confirmatory Factor Analysis (CFA), and estimating reliability. The findings reveal that: 1) The content validity of the scale is high, with Aiken's V index ranging from 0.75 to 1, 2) All 26 items in TUML scale have good loading factor, which effectively represent the underlying variables of the construct; (3) The scale exhibits good reliability with composite realibility coefficient and Cronbach's Alpha value are 0.946 and 0.941 respectively. These findings indicate that the TUML scale instrument has been proven to be valid and reliable, meeting the criteria for suitability to be used in measuring teachers' understanding of mathematical literacy. All the results are discussed, along with their implications for practice and suggestions for future research. © 2026 Author(s).
IAIN Bone, Yogyakarta State University, South Sulawesi, Indonesia; Universitas Islam Negeri Raden Intan Lampung, Indonesia; University of Hasyim Asyári, East Java, Indonesia; Patompo University, South Sulawesi, Indonesia
