Design
A between-subjects design was used in the experiment, with the instructional method – traditional instruction plus extra computer-based practice (traditional condition) versus traditional instruction plus inquiry learning within a virtual lab (virtual lab condition) – as the
independent variable. Participants were randomly assigned to either the traditional condition or the virtual lab condition. Students in both conditions followed the same full, regular
electricity curriculum. This curriculum in which the experiment was embedded contained
the following courses: a textbook-based course, Electricity Theory, and two practical
courses, Measuring Electricity and Workplace Practice. The courses in the curriculum
lasted three months or more. The time span of the experiment was nine weeks, with one
session every week. These nine sessions formed a relatively small part of the entire electricity curriculum, but the experiment aimed to cover only the period during which simple DC
circuits were treated in the regular curriculum. In the traditional condition, instruction was
supplemented with additional practice (based on traditional instruction) on topics treated in
the main curriculum. In the virtual lab condition, the traditional instruction was supplemented with inquiry learning in a virtual lab, also on the topics treated in the main curriculum. Except for these nine sessions, all courses and activities were the same for all participants.