Using a conceptual change text as a tool to teach the nature of science in an explicit reflective approach

One of the most important aims of science teaching is to create a scientifically literate society. The fast developments existing in the field of science, the products which are produced according to the scientific developments coming into nearly in every field and help shape our lives have increased the importance of scientific literacy. The goal of all students’ as scientifically literate forms the centre of various science education reform documents such as Association for the Advancement of Science (AAAS, 1993), the National Research Council (NRC, 1996) and science curriculum of a lot of individual countries (e.g. England, The USA, Canada, Australia, New Zealand, Zambia, and Turkey). The nature of science is handled as the most important component of scientific literacy, and understanding the nature of science is more important than knowing basic science concepts, principles and laws (Solomon, 2001). Understanding the nature of science contributes to science teaching from a lot of angles. For example, the students who know how scientists obtained scientific knowledge are able to solve the problems they come across in their daily life with scientific methods (Driver et al., 1996). Currently, it is accepted that tight bonds should be built between school knowledge and daily life, and it is believed that teaching the nature of science is worth spending resources on even for this benefit alone. People come across a lot of scientific knowledge while reading news, watching TV and listening to the radio. Some scientific knowledge such as global warming, environmental pollution, lack of energy sources, nuclear energy, studies on root cells, cloning and genetically modified food, etc. are discussed all over the world. An educated individual is expected to have a general knowledge about these topics. Understanding the nature of science affects the individuals’ interpretation of scientific knowledge, their realization of social problems and decision-making in discussions (Sadler, Chambers and Zeidler, 2004). Scientific knowledge after 1990s is referred to as the information age. A lot of people from past to present and different societies contributed to science. Each scientific study that was conducted lit the way for the subsequent studies. The life we have is the product of scientific studies. Understanding these qualities of science requires appreciation as a component of a modern society (Driver et al., 1996). Science can’t be done alone. Although scientists complete their studies on a particular topic individually, they have to present the results obtained to a scientific community. Results that are not approved by a scientific community do not hold validity. Due to all these reasons, the scientists follow rules that are accepted by the scientific community in every stage of their studies. Understanding the nature of science improves understanding the norms of the scientific community and it provides norms in alignment with the general values of the society (Driver et al, 1996; NRC, 1996; McComas, 2000). In addition to all these, learning the nature of science affects learning the other science subjects (Chin, 2005). The students who do not understand that scientific knowledge is temporary, who believe that science introduces facts about the earth and who do not realize that scientific knowledge is not only made up of the results of observations tend to memorize the knowledge they are presented instead of thinking of them (Akerson, Morrison and McDuffıe, 2006).

Although consensus of views is not reached on the definition of the nature of science, the aspects of the nature of science that the students at the K–12 level acquire are determined in the reform documents of science teaching and the studies conducted in this field. The studies conducted revealed that the students at different learning levels (Griffiths and Barman, 1992; Flegg and Burke, 1995; Dawkins and Dickerson, 2003; Huang, Tsai, and Chang, 2005; Kang, Scharman and Noh 2005; Arslan, Doğan-Bora and Çakıroğlu, 2006; Küçük and Çepni, 2006; Muşlu and Macaroğlu-Akgül, 2006), the teachers and the prospective teachers (Abd-El-Khalick, Bell, and Lederman, 1998; Yakmacı, 1998; Murcia and Schibeci, 1999; Gücüm, 2000; Tairab, 2001; Erdoğan 2004; Bora, 2005; Chin, 2005; İrez, 2006) had a naive/inadequate view of the nature of science, and they had misconceptions about concepts. The aspects of the nature of science are introduced in the table below, and the expressions related to these aspects that are in the mind, but in reality are myths, are summarized.

Table I: Aspects of the Nature of Science and Incorrect Ideas

Nature of Science aspect	Explanation to be accepted	Misconceptions
A general view on science	Science investigates the natural world in detail in order to gain information about it. Science cannot answer all the questions. For this reason, science is a special way of knowing (İrez, 2004).	Science introduces the facts about the earth (Dotger, 2006; Abd-El-Khalick and Lederman, 2000b), so science is a cluster of information whose accuracy is proven (Sutherland and Dennick, 2001). Furthermore, science and technology are the same concepts. A lot of people believe that TV, computers, rockets, fridges, etc. are science (Mc Comas, 2000). For example, the invention of the telescope after the invention of the lenses is a science.
Temporary	Scientific knowledge is both reliable (people can trust scientific knowledge) and temporary. Errors can be overcome or deficiencies can be completed by having new data about a specific topic. Sometimes, interpretation of present data with a new viewpoint can change the available knowledge (Akerson, Morrison and Mcduffıe, 2006). In this context, scientific knowledge is not absolute facts, but the best explanations that are accepted today.	Scientific knowledge is absolute, and it doesn’t change. Some researches reveal that students (Freidman, 2006; Khishfe and Abd-El-Khalick, 2002), prospective teachers and teachers (Murcia and Schibeci, 1999; Abd-El-Khalick and Lederman, 2000b) and even PhD students (İrez, 2006) have inadequate concepts about science. They believe that science is temporary. For example, it was proven that light is an energy source and this knowledge never changes.
Experimental	To validate the scientific knowledge, true data is needed. Scientific knowledge occurs as a result of the observations related to natural phenomenon and depends on the observation and measurement results. (AAAS Project 2061).	Experiments are done to only prove the accuracy of the scientific knowledge (Abd-El-Khalick and Lederman, 2000b). For example, experiments are important in science if you do an experiment in public, everybody believes you. Another example is that you can make everybody believe that white is made up of all the colours by using a light prism.
Imagination and creativity	Scientists use their minds and dreams to invent explanations. Scientists have to fill in the missing parts of the puzzle to make data more understandable and to set a final picture in order to see what the event is like when they have limited data. Imagination and creativity are important in this process. (Abd-El Khalick, Bell & Lederman, 1998; Küçük, 2006).	Scientific knowledge must be objective. Scientific knowledge is obtained by an experiment or an observation and the result is to achieve objectivity. Imagination and creativity prevent the results from being objective (Abell, Martini and George, 2001; Khishfe and Abd-El-Khalick, 2002; Murcia and Schibeci, 1999). For example, scientists calculated the speed of the light mathematically as 300.000km/s by doing a lot of experiments in very big laboratories.
Subjective	It is nearly impossible for the scientific knowledge to be completely objective. Because socio-cultural values, pre-concepts and paradigms adopted affect scientists’ results (McComas, 1996; McComas, 2000). For example, there are different views about global warming, the formation of universe and the extinction of dinosaurs.	Scientists gather data carefully, analyse and follow a process to come to a conclusion. For this reason, scientists who work on the same topic do similar experiments, and obtain similar data that can’t acquire different results. (McComas, 2000). For example, technology has developed rapidly. If scientists have the same technical equipment, such as microscopes and telescopes, they can reach the same results as each other.
Socio-cultural	There is a relationship between science and society. While scientific changes cause the society to develop and change, scientists are affected by the needs, traditions and customs and religion of the society they live in. Having this perspective, firstly we should appreciate to those societies and the people who contribute to science. Moreover, this perspective supports the image that the scientists won’t be objective. In teaching science of socio-cultural nature, the materials used are related to scientific developments; while the subject matter is generally being taught, the studies of the scientists who contributed to this field, the life stories of the scientists and the society and the culture where they lived and so on is also taken into account. These materials can be used differently. For example, studies on scientists help to prepare texts that tell the structure of the society, and the effect this structure has on the works of the scientist and his life. In such educational practises, students are generally passive. If there is a condition to be repeated in educational environment, there are practises where the students set up a hypothesis collect data and test it, have discussions, and the process is student centred. Such practices as special case studies (Wong et al., 2008) and cartoons (Costa da Silva, Correia and Infante-Malachias, 2009) are used in order to attract the attention of the students, to better activate their learning environment, and in other words, to obtain more positive results from learning.	Students easily accept the fact that scientific developments are generally effective for society. However, there are misunderstandings about the changes, which resists the effects society has on the science. Studies that scientists conduct are independent from society. Race, religion, traditions and customs of the society where the scientist live do not affect their studies that are conducted. For example, Edison invented the light bulb, and society was out of tbe dark. However, Edison was not affected by the society he lived in. He invented the light bulb while working long hours in the laboratory.
Observation and inference	Scientists obtain new data through experiments and comprehensive observations. The data obtained requires interpretation. Scientists make implications about their pre-conceptions by using their cognitive processes such as implication. Observations are attained directly through the senses, but implications are not reached directly through the senses. For example, measuring the average global warming and carbon dioxide levels represents the observation of scientists. Depending on these observations, the scientists’ proposed results about the amount of carbon dioxide and global warming in the future are implications (Abd-El Khalick, Bell & Lederman, 1998; Küçük, 2006).	Scientists need to see or feel the thing which they work on to learn something about nature. (Khishfe and Abd-El-Khalick, 2002; Akerson, Morrıson and Mcduffıe, 2006). Scientists observe the sky by using telescopes, and they share the results of the observations with us.
Nature of law and theory	Theory and laws are different forms of scientific knowledge and serve different functions. Laws are generalizations about the natural phenomenon are observed. Theories are the explanations of these generalizations. Theories do not become laws depending on the evidence, but they increase evidence and make theories more reliable. (Dagher, Brickhouse, Shipman and Letts, 2004).	Laws are made through direct observations, and their accuracy can be proved easily. (Dagher, Brickhouse, Shipman and Letts, 2004). Theories are immature laws and they become laws when enough proof is obtained (Griffiths and Barman, 1992; Abd-El-Khalick and Lederman, 2000b; Yalvaç, Tekkaya, Çakıroğlu and Kahyaoğlu, 2007). Theories change, but laws are absolute facts and they do not change. (Griffiths and Barman, 1992; Abd-El-Khalick and Lederman, 2000b; Gürses, Doğar and Yalçın, 2005).

Because the nature of science is not understood well enough, it has brought up the issue of how effectively this subject will be taught. Implicit, explicit reflective and historical approaches are the three basic approaches that are used in teaching the nature of science. Research reveals that (Abd-El-Khalick and Lederman, 2000a; Abd-El-Khalick and Lederman, 2000b; Khishfe and Abd-El-Khalick; 2002) the most effective method of teaching the nature of science is the explicit reflective approach. However, this approach is insufficient in teaching some of the aspects of the nature of science. For example, Çelik and Bayrakçeken (2006) aimed at making the teacher acquire a constructive point of view about the nature of science in a science, technology and community course. The nature of science was taught with the explicit reflective approach that was based on research in the course. But, the course affected the prospective teacher’s definition of science in a negative way. After the course, it was determined that the participants defined science as a cluster of knowledge and the teacher confused science with technology. The course did not turn out to be effective in understanding the nature of the models. In a study conducted by Akerson, Morrison and Mcduffıe (2006), a course was organized for pre-service elementary teachers where they were taught the nature of science by explicit reflective method, and its effects were evaluated. The students’ concept of science before the course, at the end of the course and 5 months after the course were compared. It was found that the students’ point of view towards science showed great improvement, but they couldn’t retain the new concepts they acquired 5 months after the course, and they returned to their old concepts. Consequently, new expansions are needed to increase the effectiveness of the explicit reflective approach. All teaching theories accept that pre-knowledge, concepts and experience effective in learning new information. The students, just as in the other science subjects, come to the classes with various experiences and points of view that they formed related to their experiences about science. Thus, before starting to practise the activities, which aim at developing the understanding of the nature of science, the students are required to review their own perspectives they have acquired and discover their misunderstandings (Kang, Scharman and Noh, 2005). It is suggested that the explicit reflective approach is used within the conceptual change philosophy (Abd-El-Khalick and Lederman, 2000a; Abd-El-Khalick and Lederman, 2000b; Khishfe and Abd-El-Khalick, 2002).

Educational researchers have shown interest in conceptual change since 1970s. The theorists made some explanations about what conceptual change was and how it was achieved. The simplest explanation of conceptual change is defined as the change of students’ insistent views that do not match the explanations of a scientifically accepted event. Hewson (1992) defined change in three forms. Firstly, students leave the pre-conceptions they acquired completely, and they acquire the desired concepts. Secondly, the pre-conceptions the students acquired might have both incorrect and acceptable aspects. In such circumstances, correcting the incorrect part is also a conceptual change. Finally, students have limited experiences about the concept that lead to their misconceptions. When completing absent concepts, creating a new cognitive organization is also regarded as a conceptual change. Various strategies such as concept maps, analogies, prediction-explanation-observation and cognitive contrast are used to provide conceptual change. When literature was analysed, some techniques and models of conceptual change were tried with the nature of science education. For example, Biernacka (2006) used the Common Knowledge Construction Model, Mumba et al. (2009) used the four-stage model suggested by Posner et al. (1982) during the teaching of the nature of science. Kattoula et al. (2009) prepared research-based concept maps about the nature of science. They used these concept maps both in teaching the nature of science and collecting data. Kienhues et al. (2008) used sentences that have the potential to change the epistemological beliefs in the refutational texts which are prepared to correct conceptual errors about genetics. For example it was emphasised that DNA fingerprinting methods wouldn’t give certain results, and the errors that can appear in DNA fingerprinting, resulted from refutational texts. However conceptual change texts oriented on the aspects of the nature of science and the explicit reflective approach were not found in the literature.

Conceptual change texts are texts that activate the students’ misconceptions, present common misconceptions, and try to make the learner comprehend explanations that are scientifically accepted. According to Guzzetti (2000), conceptual change texts are one of the best strategies to provide conceptual change and make permanent conceptual changes. Conceptual change texts were prepared and used for different subject matter ppreciation such as blood circulation (Alkhawaldeh, 2007), resolution balance (Önder and Geban, 2006) energy in chemical reactions (Taştan, Yalçınkaya and Boz, 2008), electro-chemical batteries (Yürük, 2007) and cellular respiration (Al Khawaldeh and Al Olaimat, 2009). Conceptual change texts contribute positively to correct conceptual mistakes in all subject areas. When the relevant literature is reviewed, it can be seen that the preparation process of conceptual change text is not thoroughly introduced. Moreover, the teachers who want to overcome their own misconceptions experience difficulties during the practise and development of conceptual change texts (Akpınar, Turan and Tekataş, 2004; Yip, 2004; Taşlı, 2005). The aim of this study was to prepare conceptual change texts to teach the aspects of the nature of science within the context of the light unit at the 7th grade elementary level. This was introduced during the development of the texts and the pilot process of the implementation.