In the first article of this issue, Lee et al. (2024) present a systematic review of academic articles from 1990 to 2021 focusing on teachers' data literacy. The aim of the article is to refine the understanding of teachers' data literacy and contribute to updating its conceptual clarity. The authors build on previous reviews and frameworks in this area and recognise further developments, for instance, that teachers' responsibilities extend beyond teaching, the growing significance of data literacy in the context of technological advancements and teachers' personal dispositions in data literacy research. The methodology involved a systematic literature search following PRISMA guidelines, which resulted in identifying 95 descriptive codes organised into five dimensions: knowledge about data, skills in using data, dispositions towards data use, data application for various purposes and data-related behaviours. These dimensions highlight the multifaceted nature of teachers' data literacy, extending beyond knowledge and skills to include attitudes, behaviours and engagement in professional development.The second paper by Kim et al. (2024) investigates the characteristics of principal feedback associated with high-quality instruction in the context of the Every Student Succeeds Act (ESSA) in the USA. According to the authors, the ESSA allows states greater autonomy in education, prompting a focus on principals' instructional This issue addresses various forms and aspects of feedback practices, including teachers' competences and the need for professional development, assessment for learning and the role of stakeholders in shaping assessment policies and practices.