Using analogies to prevent misconceptions about chemical equilibrium

Nowadays, many researchers accept that students’ misconceptions should be taken into account during the curriculum development and when creating teaching materials. Students' meaningful understanding of scientific concepts and topics has an important role for science education programs in order to attain their goals (Kiliç & Saglam, 2009). For this reason, in this study, it was aimed to investigate the effectiveness of analogies on preventing students’ misconceptions. The use of analogies to teach chemical equilibrium has been discussed for many years. In the literature review, there was found to be different analogies for the explanation of chemical equilibrium, but these analogies represented specific aspects of chemical equilibrium, such as dynamic aspect and the application of Le Chatelier’s principle. In other words, a few analogies demonstrate both other aspects of chemical equilibrium like equality of rates, reversibility, calculation of the equilibrium, constant equilibrium and its dynamic aspect and the appliation of Le Chatelier’s principle.

Analogies developed in this research aim to make new, abstract concepts such as dynamic aspects of chemical equilibrium, applying Le Chatelier’s principle, reversibility, equality of rates and calculation of the equilibrium constant more concrete and support the learning process.

The findings of the study proved that although there were no significant differences between experimental and control groups in each high school before the instruction (p>.05), significant differences were found between groups after the instruction (p<.05). According to the results of the post-test, mean scores of experimental groups were higher than the control groups. Both this data and individual interview results showed that teaching with analogies have a positive effect on students’ understanding and also prevented fundamental misconceptions. Though analysis of interviews indicated that both experimental groups and control groups have misconceptions in the areas related to approach to equilibrium and changing equilibrium conditions, these misconceptions condensed in the control groups. In the teaching of these concepts, in addition to analogies that we used in this study, using different technologies or methods, such as computer-based activities and laboratory activities, could be suggested. Also, it was determined that the percentage of correct explanations in the experimental groups was higher than control groups according to interview results. This study is evidence that teaching with analogies is an effective teaching method for higher learning achievement and in preventing misconceptions. In this respect, we thought that the present study would be an important source for the chemistry teachers in Turkey as well as that in other countries.

From some explanations to first interview questions, we have concluded that the students’ misconceptions about chemical equilibrium generally originated from their experiences in everyday life (such as SA13, SB9). Accordingly, when preparing teaching programs and materials, it is very important that students’ prior knowledge is determined.

In this study, it was observed that a semi-structured interview consisting of five questions is very effective in determining misconceptions and developing a deeper understanding of the students. Some misconceptions that were determined through the interview, such as at equilibrium, concentrations of reactants and products are equal, no changes occur; adding of reactants to an equilibrium reaction does not effect the concentration of substances; and increasing of temperature does not influence the rate of reverse reaction, are similar to the literature (Banerjee & Power, 1991, Griffiths, 1994; Özmen, 2007; Sözbilir, Pinarbasi & Canpolat, 2010). Existence of these similar misconceptions shows that many learners do not understand chemical equilibrium correctly; however, these learners were studied in different counties. Also, it was found that some chemistry teachers had some misconceptions about chemical equilibrium, much like their own students (Cheung, 2009; Cheung, Ma & Yang, 2009).

In this case, curriculum developers and teachers should take some responsibility to make teaching more effective and to overcome misconceptions. For example, high school chemistry curriculum should focus more on samples related to real life situations and examples. In that way, many chemistry topics like chemical equilibrium should be easier to learn. In addition, some practical activities related to chemical equilibrium could take place in the curriculum. Thus, high school chemistry curriculum in Turkey was modified in 2008-2009 academic year. New chemistry curriculum based on the principles of the constructivist approach. This was a radical shift from a teacher-subject based approach to student-based approach. Firstly, new chemistry curriculum was implemented in the ninth grades of high schools in the 2008-2009 academic year. Eleventh graders’ chemistry curriculum, which includes the subject of chemical equilibrium, will start to be implemented in 2010-2011 academic year. So, we do not yet have enough information to evaluate this new chemistry curriculum. However, according to our informal talk with chemistry teachers, it emerged that they were not adequately informed about the program and could not understand the program based on constructivism. For an education program to be successful, it is very important that teachers who are leading the program have the knowledge and skills required (Kirikkaya, 2009). For this reason, teachers should be given in-service courses concerning contemporary methods, technique, measurement and evaluation, required by the program. Particularly, a focus should be on how activities develop and apply the in-service courses, as most teachers do not have enough competence regarding these types of activities.

Another responsibility that teachers should be aware of is students' prior knowledge and misconceptions, because they are strong predictors of student achievement in chemistry. Because of this, teachers should control students’ prior knowledge before teaching of subject matter (Özmen, 2007). In this process, teachers should be able to use diagnostic tests or word association test for determining students’ prior knowledge. Then teachers should select a suitable teaching method according to students’ prior knowledge.

Researchers have shown that the teacher centered traditional approach fails to prevent misconceptions (Acar &Tarhan 2007, Bodner 1986; Felder 1996). So, it is very important to develop alternative methods that can correct or prevent students’ misconceptions. One of the alternative methods is using analogies. Teaching with analogies allows students to actively participate in the learning process. Analogies can help students relate new information to prior knowledge, to integrate information for one subject area into another, and to relate classroom information to everyday experiences. In this process, students observe, record data and conclude that these skills are important in terms of converting abstract knowledge into concrete knowledge, learning and overcoming misconceptions (Yildirim et al., 2010). Previous researchers have also emphasized that analogies support meaningful learning and help students to construct topics easily; these are referred to as hard issues and include abstract concepts like chemical equilibrium (Harrison & Jong, 2005; Ganaras, Dumon & Larcher, 2008, Kargiban & Siraj; 2009). In addition, analogies are funny for many students (Sarantopoulos & Tsaparlis, 2004). Therefore, using analogies to teach chemistry may positively influence students’ motivation to study chemistry. In conclusion, similar studies should be continued, and analogy activities should be developed for chemistry lessons as well as the other science fields.