An analysis of prospective chemistry teachers’ cognitive structures through flow map method: The subject of oxidation and reduction

Flow maps were prepared in this study in order to analyse prospective chemistry teachers’ cognitive structures in relation to the subject of oxidation and reduction. An examination of the flow maps showed that participants were able to define the concepts of “activity, oxidation, reduction, oxidiser, reducer, and oxidation state” in general. It was also found that prospective chemistry teachers often gave such examples as the activities happening in a battery, electrolysis, rusting of iron, and instances of burning, for the activities based on oxidation and reduction reactions. Therefore, it was clear that the prospective chemistry teachers had an accumulation of current knowledge on the subject. The flow maps prepared in order to determine the status of this accumulation of their current knowledge—this cognitive structure—from the perspective of extent, richness, integratedness and accuracy were analysed according to the quantitative variables suggested by Tsai (2001). According to Tsai and Huang (2002), flow maps offer more information for analysing the variables related to cognitive structure (extent, correctness, integration, availability, analyses of information-processing strategies) than other methods. In a similar way, Anderson and Demetrius (1993), Bischoff (2006), Chang, Yeh, and Barufaldi (2010), Dhindsa and Anderson (2004), and Tsai (2001) also used flow maps in their studies to analyse students’ cognitive structures. Karagöz Şahin (2004) also analysed the conceptual dimension and dynamics of students’ cognitive structures and information-processing strategies, as well as their misconceptions, by using flow maps.

On examining prospective chemistry teachers’ flow maps in accordance with all the quantitative variables used in presenting cognitive structures, it is found that P8 had the largest comprehensive cognitive structure, P4 had the medium comprehensive cognitive structure whereas P1 had the narrowest comprehensive cognitive structure. The small number of recurrent linkages, in particular, displays quite limited opinion connections and a weak development of content schema (Bischoff & Anderson, 2001). Moreover, through the flow maps examined, it was found that prospective chemistry teachers had knowledge insufficiencies in their cognitive structures. For instance, not all of the participants mentioned the concept of “activity”, and those who mentioned it defined it as “willingness to react”. Only P4 mentioned the relations between willingness to react and elements’ bias to gain or lose electrons, but none of them mentioned the relations between willingness to react and whether or not reactions can occur spontaneously. Nor did they mention the relation between “activity” and “the order of activity”. They did not mention the relations between the oxidising and reducing tendency of a substance, either. They defined the concepts of “oxidiser” and “reducer”, but they could not set up relations, such as an oxidising substance was a reduced substance and a reducing substance was an oxidised substance simultaneously. The prospective chemistry teachers listed examples of actions based on oxidation and reduction reactions, yet none of them mentioned “termite”. Selvi and Yakışan (2005) in their research aiming to exhibit prospective biology teachers’ cognitive structures related to the carbon cycle through flow maps, found that there were insufficiencies in the extent of knowledge related to the carbon cycle during recall and in the relations between pieces of knowledge. The researchers also found that students could not fully describe in writing the basic stages of the cycle, and that they ordered their statements in a way so as to set up linear relations rather than to describe the cycle. Bischoff et al. (2010) aimed to analyse the development of prospective science teachers’ knowledge structures related to oxidation and reduction. Having analysed the prospective teachers’ knowledge structures through flow maps, the researchers found that the prospective teachers’ knowledge structures were not combined consistently around correct statements.

Prospective chemistry teachers’ misconceptions were also determined through flow maps. Those misconceptions are important in that they provide information especially concerning the accuracy of cognitive structures because the smaller the number of misconceptions, the more accurate the cognitive structure (Tsai, 2001). On examining participants’ misconceptions, it was found that they had misconceptions related to the concept of “oxidation state”. In their research Zhou, Wang, and Zheng (2015) attempted to discover high school students’ cognitive structures through flow maps, and to exhibit the learning difficulties they had in relation to ethanoic acid. As a result of the content analysis of flow maps, it was concluded that most of the students knew the main ideas about ethanoic acid, but that they were lacking details in parts and that their misconceptions were mostly related to molecular structure and with the esterification reaction. Chin-Chung and Chao-Ming (2001) also used flow maps to assess students’ cognitive structures related to biological reproduction and their information processing tendencies, and they also distinguished misconceptions.