In the first paper, we describe the development of a data use framework, as a start of the EU Comenius project. Case studies were conducted to study the use of data, as well as the factors influencing data use in these countries. In each country (Germany, The Netherlands, Lithuania, Poland, and UK) as least five respondent of two schools were interviewed. Also, documents (e.g. policy plans, literature, and OECD reports) were collected to describe the educational policy (related to data use) in each of the countries. Qualitative analyses of these results led to the development of a data use framework. The results show that policy may influence data use in the different countries. Moreover, characteristics of the organization, characteristics of the data and user characteristics may influence data use. The different enablers and barriers influence the extent to which data are used to base decisions on. We distinguish between three different types of data-driven decision making: data use for school development purposes; for accountability purposes; and for instructional development. If data are used for these different purposes, this may lead to stakeholder (e.g. teachers, school leaders, parents) learning and student learning.