The contexts in which computer-based scaffolding is used can vary widely. Such variation is by learner population (e.g., grade level and other characteristics such as achievement level and socioeconomic status), subject matter (i.e., science, technology, engineering, and mathematics), and instructional model with which scaffolding is used (e.g., design-based learning and problem-based learning). I describe these variations, and note accompanying variations in effect size estimates. Notably, scaffolding had its strongest impact when students were (a) at the adult level, (b) engaged in project-based learning or problem solving and (c) from traditional learner populations.
Rationale for this ChapterTo begin this chapter, it is important to discuss the need for a consideration of the context of use of computer-based scaffolding. After all, in its original definition, scaffolding was provided on a one-to-one basis to toddlers who engaged in unstructured problem-solving (Wood, Bruner, & Ross, 1976). All structure to the problem-solving activity was provided by the scaffolding process itself. This was practical when there was one teacher for each student, but lost its practicality as a single source of support when using scaffolding in formal schooling. After all, when a teacher can work on a one-to-one basis with one student for an unlimited time span, the teacher can continually assess what structure is needed, and provide it. This is hard to beat in terms of effectiveness. But in formal school settings, teachers very rarely have this opportunity. So, as researchers turned their attention to how instruction could be centered on problem-solving in formal education, it was important to think about additional ways to provide structure to student learning in 56 3 Context of Use of Computer-Based Scaffolding this context (Palincsar & Brown, 1984;Schmidt, Rotgans, & Yew, 2011). This was often accomplished by pairing scaffolding with formal problem-centered instructional models (e.g., inquiry-based learning and problem-based learning; Crippen & Archambault, 2012;Hmelo-Silver, Duncan, & Chinn, 2007;Kolodner et al., 2003). Such formal, problem-centered instructional models needed to be paired with support for students' reasoning abilities, and instructional scaffolding (one-to-one and, later, computer-based and peer scaffolding) fit such a need nicely.A natural question is whether the specific problem-centered instructional model with which scaffolding is used influences scaffolding's efficacy. This is an empirical question. It is beyond the scope of this book to investigate variations in the efficacy of one-to-one scaffolding and peer scaffolding based on the specific problem-centered instructional model with which it is used. But I do investigate how the efficacy of computer-based scaffolding varies based on the problem-centered instructional model with which it is used.Deploying scaffolding in formal education environments also entailed an expansion of the age groups with which scaffolding was used. Computer-based...