Studies on writing development have grown in diversity and depth in recent decades, but remain fragmented along lines of theory, method, and age ranges or populations studied. Meaningful, competent writing performances that meet the demands of the moment rely on many kinds of well-practiced and deeply understood capacities working together; however, these capacities’ realization and developmental trajectories can vary from one individual to another. Without an integrated framework to understand lifespan development of writing abilities in its variation, high-stakes decisions about curriculum, instruction, and assessment are often made in unsystematic ways that may fail to support the development they are intended to facilitate; further, research may not consider the range of issues at stake in studying writing in any particular moment.To address this need and synthesize what is known about the various dimensions of writing development at different ages, the coauthors of this essay have engaged in sustained discussion, drawing on a range of theoretical and methodological perspectives. Drawing on research from different disciplinary perspectives, they propose eight principles upon which an account of writing development consistent with research findings could be founded. These principles are proposed as a basis for further lines of inquiry into how writing develops across the lifespan.

Research on the texts of apprentice academic writers has found that they often exhibit weaknesses related to presenting an authoritative argumentative stance. This study rendered explicit linguistic resources for stance-taking and engaged advanced L2 writers in exploring stance expressions in published research. Both linguistic and language learning theories informed this study. Seven Mandarin-speaking learners of English from fields in social sciences engaged in three writing sessions in which they consulted a concordance tool organized and created to present genre moves (Swales 1990; 2004) and engagement strategies (Martin & White, 2005) used by academic authors in research introductions. Analysis of their drafts showed improvement in rhetorical move structure and stance deployment after using the tool. They were found to be more accurate in applying and identifying stances that present assertive claims and factual statements than moderately assertive stance expressions that present expansive meanings. Despite some success in learning, close text analysis reveals that more help is needed to support students in deploying appropriately assertive claims, substantiating strong claims, and managing their stance expression across several clauses. Overall, this study found that an explicit approach to learning about authorial stance has the potential to raise L2 writers’ consciousness and improve their writing.