This article describes an action research project conducted at two public schools in an urban center in the province of New Brunswick in eastern Canada. The project involved the development of and experimentation with a model for the instruction of writing (ÉCRI – écriture cohérente et raisonnée en immersion) at both the elementary and middle-school levels. Research questions focused on gaining insight into best practices for teaching writing through practitioner dialogue in professional learning communities (PLCs), classroom observation and videotaping, teacher reflections, and stimulated recall. The data gathered were analyzed to determine similarities and differences between the implementation of the model in elementary and middle school settings as well as second-language and first-language learning contexts. Results of the study demonstrate the applicability of this multi-phase model at both levels and in both learning environments and the adaptations necessary to meet the needs of learners in these contexts.