Few studies address feedback and teaching methods that lead to good writing development in primary school. The purpose of this thesis was to contribute knowledge about the teaching of story writing in primary school through a learning study in which peer feedback was implemented. The research questions guiding this thesis were: What are the critical aspects of the learning object?, How can these critical aspects be highlighted in teaching to make the learning object visible? and In what ways and with whom does scaffolding occur in story writing? To collect data for the study, qualitative methods such as structured observation, collected student narratives and worksheets from peer feedback were utilized through a learning study based on variation theory and complemented with sociocultural concepts. The results of the study showed that few students revised their stories after peer feedback was implemented. Furthermore, the critical aspects of the learning object identified in the study were the use of punctuation, basic writing rules and chronological order. The critical aspects could be highlighted in teaching to make the learning object visible through modeling and working with peer feedback. To support story writing, teachers could offer students scaffolding through support images, asking questions, providing feedback and modeling. However, the results also indicated insufficient scaffolding where teachers provided feedback that did not meet the students' needs. Finally, students could become ‘the more competent peers’ for each other by acting as role models and supporting each other by actively interacting and sharing explanations and thoughts.