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Asia-Pacific Forum on Science Learning and Teaching, Volume 16, Issue 2, Article 7 (Dec., 2015) |
Are historical chemical controversies useful for promoting students’ assessment of evidence relating to experimentation in science and scientific communication? This is the first question addressed in this study. To answer it, our investigation has used the eighteenth-century chemical controversy between Scheele, Priestley and Lavoisier recreated in Scene 8 of the play “Oxygen” (Djerassi & Hoffmann, 2003). According to the results (Tables 1 and 2), this historical controversy offers relevant information (evidence) that can be utilized in the chemistry classroom to promote learners’ assessment of evidence.
Moreover, the results indicate that students are more inclined to evaluate evidence relating to experimentation in science (Table 1) than evidence relating to scientific communication (Table 2). Both types of evidence are decisive in the advancement of chemistry (Lehman & Bensaude-Vincent, 2007; Nielsen, 2013). Based on this finding, it is plausible to suggest that the chemistry classroom should become a place for enhancing students’ assessment of evidence. More precisely, class activities should be planned to offer greater opportunities for learners to evaluate evidence explicitly in decision-making. This is an imperative condition for enriching evidence evaluation by students. Thus, the results of this research contribute toward the promotion of critical thinking by students through supported argumentation in the chemistry classroom itself. This is consistent with McDonald and McRobbie’s (2012) reflections. According to these authors, it is important to:
Also introduce the notion of supported argumentation instruction to describe an instructional approach to argumentation that does not explicitly guide learners in understanding the skills of argument, but instead provides prompts and suggestions for constructing arguments or evaluating evidence (p. 972, italics added).
What are the opportunities for and obstacles to the use of historical chemical controversies for enriching students’ assessment of evidence? This is the second question addressed in this study. One obstacle to the promotion of critical thinking in the chemistry classroom is that pupils often make assertions without evidence (Kogut, 1996). This is a good reason to include evidence evaluation in the teaching of chemistry. Thus, if students evaluate evidence adequately, they would have more chances to use it. Often, as pointed out by Kogut (1996), Silverman (1992) and Yun and Kim (2015), learners consider that scientific questions necessarily trigger unambiguous, unique and correct answers. In this sense, the historical chemical controversy between Scheele, Priestley and Lavoisier used in this study shows that the assessment of evidence promotes a more informed understanding of the nature of science.
In the controversy, “Who discovered oxygen?”, all the evidence provided by Scheele, Priestley and Lavoisier is correct and valid (Bensaude-Vincent & Van Tiggelen, 2003). In this study, the expectation was that the participants would consider most of the evidence provided by each chemist to be “decisive”. However, the results suggest that students are not accustomed to evaluating evidence from historical chemical controversies. Scene 8 of the play “Oxygen” (Djerassi & Hoffmann, 2003) recreates valuable evidence that could serve to answer the question, “Who discovered oxygen?”. For instance, Scheele prepared the gas in 1771 (before Priestley and Lavoisier) (Evidence B, 41%; 26/63), Priestley communicated his discovery in the same year that he performed his experiment (Evidence K, 30%; 19/63), while careful weighings and experiments were integral in enabling Lavoisier to understand that the gas was oxygen (Evidence F, 63%; 40/63). Yet, none of this “decisive evidence” was widely evaluated by the participants (Tables 1 and 2).
Limitations of the Study
Evaluating evidence (Gott & Duggan, 2003; Jiménez-Aleixandre & Puig, 2012; Judge, Jones & McCreery, 2009; Pallant & Lee, 2015; Yun & Kim, 2015) and historical controversies (Archila, 2015; de Hosson, 2011; Montgomery, 2009; Niaz, 2000, 2009) are two research interest that have worked separately. In other words, this is the first study that conjugates them, not only to promote critical thinking, but also a more informed understanding of the nature of science. That said, various limitations must be addressed. It should be taken into consideration that in this study 63 participants (24 females and 39 males aged 16–17 years) evaluated evidence relating to the polemical question of who discovered oxygen. Thus, (1) the small number of participants, (2) the historical controversy chosen, and (3) the range of age are three strong limitations of the research reported in this paper.
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