This research is related to Education Development Trust's Department for International Development-funded Girls' Education Challenge (GEC) programme in Kenya. Complementing the monitoring and evaluation data gathered for the programme, this research was funded by Education Development Trust to enrich and develop a deeper understanding of girls' experiences at school in Kenya. It explores aspects of school and schooling that affect the participation and learning of marginalised girls in the Arid and Semi-Arid Lands (ASALs) of Turkana and the slums of Nairobi. The report offers a detailed, qualitative analysis of the practices and experience of education of 128 girls across 16 primary schools in these two regions. It examines: (1) Why marginalised girls in ASALs and slums participate and learn better in some schools compared to others; (2) Why there might be a higher proportion of girls enrolled in some of these schools; and (3) How reform can be supported in other Kenyan schools to increase enrolment, achievement and the completion of basic education for girls. The study involved visiting a total of 16 schools (eight in Turkana and eight in the Nairobi slums) for two days each in term two of the 2014 school year. Over the course of the research the team met with 128 girls, 53 2 teachers, 14 heads and two deputies, observed 53 lessons and carried out 48 'out-of-class' observations. Findings are presented in two chapters. The first gives the findings from each data source and the second presents a cross-case thematic analysis. The key points are described in this report. This report suggests that schools should consider how they collect fees, build positive relationships between female pupils and teachers, and encourage active and professional leadership in order to build better learning environments in which girls are more likely to complete schooling and do well. Schools also need to continue to address quality issues and maximise learning time during the school day, and ensure that girls are not inadvertently excluded from additional learning opportunities offered outside the school day.