Web-based instruction (WBI), taking advantage of the advancement of hypermedia technology, has become a popular alternative to mainstream face-to-face instruction. The potential of WBI has led to the shift of research focus to examining variables that may contribute to the success of this kind of instruction. Research has shown that the advantage of WBI lies in its affordance of nonlinear interaction (Laurillard, 1993). Nonlinearity of WBI is believed to provide individuals with learning decisions that allow them to control their sequence and pace while learning thetarget material. In addition, allowing individuals to have control over their learning also makes them more motivated
to learn (Keller, 1983).