The same university professor provided the lessons for both groups and covered the same science content. Tasks for both groups were similar and included the use of print, video, and computer resources as well as hands-on experiments, small group work, teacher-led discussions, and demonstrations. Both groups kept records of definitions, data collections, and experiment results in daily journals. The experimental group’s instruction differed from the comparison group in one aspect: the addition of the elements of PBL. For the purposes of the study, PBL followed the model defined by Howard (2002) and Long, Drake, and Halychyn (2004) for elementary school students. This model includes the following four steps: