Dataset for measuring the conceptual understanding of optics in Rwanda [version 1; peer review: 2 approved with reservations]

This dataset is an accumulation of data collected to test Rwandan physics students' conceptual understanding of light phenomena and to assess instructional tools for active learning of optics. We collected and analysed data from 251 grade 11 (senior 5) students using our Light Phenomena Conceptual Assessment (LPCA) tool and from 136 grade 10 (senior 4) students using Geometric Optics Conceptual Understanding Test (GOCUT) in 2019. Before collecting data, we designed and validated LPCA and GOCUT, and tested their reliability. Data were collected before and after students learnt about the unit of light. Both day and boarding schools in rural and urban areas were included in our sampling. Data collected were test scores from students after performing a 30-item LPCA test or 25-item GOCUT test in 40 minutes. The data may be reused to extend students' understanding of optics concepts through item analysis, analysis of school characteristics such as location and school type, or by analysing students' characteristics such as subject combinations.