Within the BeLesen* survey teachers receive feedback regarding the performance of their students in assessments. This PhD research focuses on the teachers' attitudes towards this particular system of data feedback. The poster will present - the format of data feedback which was developed within the BeLesen project and - results from the PhD project concerning the following questions. Do the teachers understand the information with which they are provided?' Do teachers use the data feedback to improve the way in which their students are supported. Do they change their teaching methods depending on the results? Do they discuss the results with colleagues or with parents? What is the general attitude of the teachers towards this kind of information/ feedback?' The results show a good starting point from which to develop more individualized feedback. Recommendations will be given for how the results of student assessments for school achievement can be more helpful for teachers. The improved coordination of the test results with the information that is communicated to the teachers - within the framework of this data feedback system - will be highlighted as a central theme. * BeLesen: Berliner Längsschnitt-Studie zur Lesekompetenzentwicklung bei Grundschülern mit Migrationshintergrund (Prof. Dr. Hans Merkens, Prof. Dr. Agi Schruender-Lenzen). A longitudinal survey on literacy in elementary school - students with migration background.