Katerina Salta

Development and application of suitable criteria for the evaluation of chemical representations in school textbooks

The study of Chemistry deals essentially with three types of chemical representations: macro, submicro, and symbolic. Research has consistently shown that students experience difficulties in understanding and interpreting the representations, in making translations between different types of representations, and in constructing them. In this study, we conducted a detailed review of existing presuppositions that define what Chemical Representations are to be included in school textbooks for the purpose of enhancing the student’s understanding of Chemistry. We then conducted a detailed analysis of the Chemical Representations included in five Chemistry textbooks. The detailed analysis revealed five criteria for the evaluation of chemical representation used in school textbooks. These criteria (C1-C5) are: (C1) the type of the representation; (C2) the interpretation of the surface features; (C3) their relationship to the text; (C4) the existence and the properties of a caption; (C5) the degree of correlation between the components comprising a multiple representation. The utility of the proposed criteria was then checked against a 10th-grade Greek chemistry textbook. The five criteria cover the basic elements required for a better utilization of chemical representations in the understanding of Chemistry. The five criteria can also be used for the analysis of existing school textbooks and as an authoring tool in designing new Chemistry textbooks.

Changes in visual/spatial and analytic strategy use in organic chemistry with the development of expertise

We present two studies that investigated the adoption of visual/spatial and analytic strategies by individuals at different levels of expertise in the area of organic chemistry, using the Visual Analytic Chemistry Task (VACT). The VACT allows the direct detection of analytic strategy use without drawing inferences about underlying mental processes. The first study examined the psychometric properties of the VACT and revealed a structure consistent with the hypothesis that it consists of two sub-scales: visual/spatial and analytic. The second study investigated the performance of 285 participants with various levels of expertise in organic chemistry on the VACT. The results showed that the adoption of analytic strategies in organic chemistry, and specifically in molecular structure, was difficult and was systematically used only by the more expert participants. The implications of this research for the teaching of chemistry are discussed.

Investigating high-school chemical kinetics: the Greek chemistry textbook and students' difficulties

In this study we present an analysis of how the structure and content of the Greek school textbook approach the concepts of chemical kinetics, and an investigation of the difficulties that 11th grade Greek students face regarding these concepts. Based on the structure and content of the Greek textbook, a tool was developed and applied to students in the form of test questions in order to investigate the difficulties that they encounter with concepts and facts of chemical kinetics. Our results indicate that the textbook presentation at several points does not take into consideration basic findings of chemistry education research, which could improve the understanding of the content, and that a large proportion of Greek students show low comprehension levels of the concepts and facts of chemical kinetics. Given the important role of the school textbook in the learning process, it seems that the structure and content of the textbook do not facilitate the conceptual understanding of the subject matter, and together with other factors contribute to the difficulties that students face regarding concepts in chemical kinetics.