Resumen
This study investigates the effects of instruction in genre writing with planning and revising activities (GWPR) on learning. This type of instruction appeared to be successful in promoting learning in several types of education. However, there are few studies on the effects on low achievers. Therefore, two studies were conducted with low-achieving students, each comprising a quasi-experimental study and a small-scale think-aloud study, both of which were embedded in regular education for low-achieving adolescents. The first study took place in biology classes (grade 7, three lessons); the second study was in mathematics classes (grade 10, six lessons). The researchers co-created writing-to-learn tasks with the teachers. The results showed positive effects on learning in mathematics classes as compared with the control group, but not in biology classes. The think-aloud study in the experimental mathematics class condition provided evidence of the learning by writing process. In the experimental biology class condition, such evidence was barely present. The results suggest that the experimental intervention in biology classes was too short for the students to grasp the essentials of learning by writing. This paper also discusses suggestions for further research and pedagogical implications.