A context-based approach to education aims to improve students' meaningful learning and uses authentic situations in which scientific concepts are applied. The use of contexts may contribute to the learning of abstract concepts such as algorithms. The selection of appropriate contexts, however, is challenging for teachers. It is therefore interesting to examine whether students can play an active role in the conception of such contexts and how designing contexts may contribute to student learning. As a case study, we investigated students' design of contexts for learning algorithms in upper secondary education. We developed lessons in which students collaboratively designed contexts and then reflected individually on all contexts proposed. At the end of these lessons, students completed a learner report. The students' design of contexts provided a remarkably wide range of learning outcomes. Students not only reported to have learned more about the lesson topic (algorithmic concepts and the application of these), but the learner reports also reflected learning about the process (learning with contexts, designing contexts, and collaboration). Our findings suggest that designing contexts contributes to active learning. The results of this study may serve as recommendations for future research concerning the role of students in designing contexts.