I take this to mean that the instructional design of the course affects achievement. What are the students asked to do? When and how? According to the authors, "SC interaction may include reading informational texts, using study guides, watching videos, interacting with computer-based multimedia, using simulations, or using cognitive support software, as well as searching for information, completing assignments, and working on projects". (Bernard, et al, 2009, 1248). How is SC strengthened?