More than ever, effective writing and proficient argumentation are imperative for full participation
in our 21st century society. This proposal combines both, as prior (inter)national findings call
attention to the fact that secondary school students’ writing, and argumentative writing in
particular, is inadequately developed. Therefore, the main aim is to gain insight in how to support all
secondary students adequately in acquiring argumentative writing. Considering prior research on
the value of conversational and cognitive strategic support, the proposal builds on and combines
both theoretical strands. 2 experiments will be set up. Experiment 1 with a 2x2 design studies
students’ argumentative writing via an intervention in 16 authentic 9th-grade secondary school
classes and will evaluate and compare the impact of class-wide teacher-led educational
interventions aiming at cognitive strategic support (i.e. explicit writing strategy instruction) and/or
conversational support (i.e. collaborative writing) on students’ writing motivation, self-efficacy,
strategy use, and argumentative writing performance. We further study whether the potential
impact of collaborative writing can be attributed to quality differences in the collaborative
interaction. Experiment 2 studies the impact of a class-wide teacher-led intervention aiming at
eliciting transactive talk during collaborative writing on the group’s argumentative writing
performance and individual student outcomes (cf. exp 1).