The goals of this development and research was to determine if C-SAW—an instructional technology designed according to principles derived from research and literature on supporting argumentative writing—could scaffold novices' cognitive and meta-cognitive processes to support the construction of argumentation that favours learning and conceptual change. The main results of a field study and an experimental study pointed to C-SAW mediating reasoning by scaffolding writing processes requiring the use of cognitive resources that would otherwise be allocated to form rather than content and reflection. Though not improving text quality, scaffolding increased argument introduction and completion correlated to increases in conceptual knowledge and changes towards less absolutist epistemic beliefs. This indicated that scaffolded written argumentation, even in the absence of text quality, may suffice to introduce new knowledge and raise awareness of one's own beliefs and certitudes regarding knowledge, making learners more open to deeper learning and conceptual change.