The study "Improving Language And Reading Skills (LARS) in children with German as a first or second language" evaluates a newly developed differentiating programme for reading in terms of its effects on the reading and language ability of second graders with German as a first or second language. The participant group consisted of 105 children. Fifty-five children belonged to the group that received the programme (LARS-group) and 50 children received traditional instruction (TI-group). The reading, spelling and language ability of each participating child were assessed before and after the programme period. The children of the LARS-group were supported over three months in terms of reading texts and completing the corresponding tasks. The texts and the tasks were adapted to the students' ability levels (three different ability levels: above average, average and below average level in reading). The results indicate that the learning outcomes for children in the LARS-classes were significantly higher for reading fluency and comprehension, but no effect was observed for language and spelling. The results suggest that the LARS programme was equally effective for children with German as a first or second language.