Junior high school and high school students are able to direct their own investiga¬tive activity, and complete all stages of scientific investigation, such as: studying complex phenomena by formulating hypotheses, controlling variables, designing experiments, collecting and analyzing information, and drawing conclusions (Tamir et al., 1982; Gott et al., 1999). These activities foster students' natural curiosity, promote scientific activity as an intellectual value, and reinforce the view that the world is subject to investigation. Furthermore, opportunities to experience science-in-the-making together with the ability to engage in discourse may lead to a better understanding of the nature of scientific research (Bell et al., 2003) .