Representations of chemical phenomena in secondary school chemistry textbooks

Abstract

The difficulties encountered by students in learning chemistry range from human factors to the intrinsic nature of chemistry. To enhance students’ understanding of chemistry, there is a wide consensus within the community of chemistry educators on the importance of and need to integrate different levels of representations in chemistry teaching and learning resources. As learning resources, textbooks are ubiquitous and usually readily available to both students and teachers. Therefore, this study investigated how chemical phenomena are represented or depicted in secondary school chemistry textbooks. We adopted a rubric developed by Gkitziaet al.(Gkitzia V., Salta K. and Tzougraki C., (2011), Development and application of suitable criteria for the evaluation of chemical representations in school textbooks,Chem. Educ. Res. Pract.,12, 5–14) to analyze the textbooks for types of representations; relatedness of chemical representations to text; and the appropriateness of captions. The results indicated the dominance of symbolic representations, followed by sub-microscopic, then hybrid and multiple representations. In all three textbooks, there was no evidence of mixed representation. While many of the chemical representations were completely related to the texts, some were unlinked. The germaneness of suitable captions in textbooks is in the explicit, brief and concise explanation that captions give to an entire representation. While our results indicated that more than half of the representations had suitable captions, there was evidence of representations that were problematic and had no captions. The implication of these results for students’ cognitive load, and the need for textbook-users to explore alternative resources that depict phenomena in 2D or 3D representations are discussed.

An Analysis of the Visual Representation of Redox Reactions in Secondary Chemistry Textbooks from Different Chinese Communities

“…In terms of the distribution of the different levels of representation from this sample, macroscopic representation is dominant among other visual representations. This finding is very different from recently reported findings on chemistry textbooks from Africa, for example, Upahi and Ramnarain [2] reported a dominance of symbolic representations for the textbooks in Nigeria. To suggest reasons for this difference, however, would be highly speculative, but the reasons may lie in different curriculum traditions and lack of practical work, more than in the aspects of culture or socio-economic development [43].…”

“…To suggest reasons for this difference, however, would be highly speculative, but the reasons may lie in different curriculum traditions and lack of practical work, more than in the aspects of culture or socio-economic development [43]. However, the curriculum orientation [34] and the function of visual representations [51] concerned with redox reactions were not defined [2]. Treagust et al [54] suggest that macroscopic representations are the basis of chemistry learning, but macroscopic understanding relies on an explanation at the submicroscopic level.…”

“…A central concept of understanding common difficulties in teaching and learning chemistry suggested in 1991 by Johnstone [1] concerns the chemical thinking needed between three representational levels, namely, the macroscopic, submicroscopic, and symbolic levels. This central concept has been used for analysis of chemistry textbooks [2]. Macroscopically, students are required to observe, for example, combustion.…”

“…As already noted, research indicates that students often have difficulties in correctly relating the different levels of representations to one another [19] even when visual representations should help students make the right connections. Therefore, it is recommended to thoroughly use visual representations of the different representational levels of chemistry in chemistry teaching and learning [2]. To meet this recommendation, it is important for teachers to know how to deal with and how to connect the different representational levels in chemistry, and how to use different representations of redox reactions content [20].…”

“…Since chemistry textbooks are the medium between chemistry and the learner [42], textbook analysis is gaining increasing interest in chemistry education in general (e.g., [2,25,43]), and in this journal in particular (e.g., [44,45]). Textbook analysis of visual representations can help to ensure that they are better used in future textbooks.…”