The National Foundation for Educational Research (NFER) was commissioned by the Department for Education and Skills (DfES) to conduct a study of primary, secondary and special maintained schools in England to assess the use of data in teaching and learning. The study sought to identify how data is used to promote learning in primary, middle, secondary and special maintained schools in England; identify good practice in the effective use of data to promote learning; investigate possible challenges to using data of this nature; and to provide recommendations to support school staff in making effective use of data to promote learning, including the future development of the Pupil Achievement Tracker (PAT). The ethos or assumption underlying the provision of data to schools is that such information leads to improvements in performance. This study gathered evidence as to the impact of the use of data in schools and the perceptions of users as to how successful this has been in raising attainment. In all types of schools, it was found that data was perceived to promote teaching and learning by facilitating: (1) more effective allocation of staff and resources; (2) performance management; (3) monitoring the effectiveness of initiatives and strategies; (4) evidence-based discussions with the Office for Standards in Education (OFSTED), local education authorities (LEAs), governors, etc.; (5) challenging expectations of staff, pupils, parents, among others; (6) transitions and transfers, particularly transitions between key stages within schools; and (7) identification of pupils' achievements and setting of targets. "Good practice" emerged from the use to which the data was put rather than specific systems or tools. A recurrent theme was that data only becomes effective if it stimulates questions about the actual learning that is taking place and how it can be developed further. This report makes a number of recommendations for schools, LEAs and policymakers. Appended to this report are: (1) copies of questionnaires; (2) schedule for focus group meetings; (3) glossary; and (4) project team. (Contains 47 tables.) [This report was produced by the Department for Education and Skills.]