2.2.3. Research instruments & procedure
For this experiment, a classical pretest-posttest design was used, with the GOC version as the experimental
sample, and the NGOC version as the control sample. Several research instruments were employed to measure the
dependent variable (knowledge acquisition) and the mediating variables (self-efficacy, cognitive load, attitude
toward behaviour, perceived usefulness, and intrinsic motivation).
To determine knowledge acquisition, a new test was designed in collaboration with a panel of experts who
reviewed and approved the test before first administration. This multiple choice test consisted of 10 items. For
instance, “What is the cause of the continental drift? A. Climate change. B. Tsunamis. C. The structure of the earth.
D. Change in fauna and flora.” The same test was used at both test moments.
A new scale was created to test the self-efficacy related to the topic covered by the presentation (Lachman &
Leff, 1989; Pajares, 1996; Pajares & Miller, 1995), namely continental drift. Eighteen items were developed that
reflect the mastery of the conceptual knowledge and skills elements. For instance, “I can label the different
components of the earth.” For each item participants were asked to give a score - on a scale of 0 to 100 - to the