The effect of the case-based learning method on high school physics students' conceptual understanding of the unit on energy

Starting from the reality that physics is an essential part of nature and technology and almost every other field, exposing students to physics by placing them in contexts that will arouse their interest and curiosity (sports, health, environment, technological tools, etc.) will provide the opportunity to create a need or a reason for learning. By associating physics with daily life, the idea that physics can be carried outside of the classroom as a science that can explain us the phenomena occurring around us is a notion that must be developed (Turkish Ministry of National Education, Board of Education [TTKB], 2013). In this context, the student-centered active learning method of Case-Based Learning-CBL forms the focus of this study.

In recent years, considerable attention on active learning have been established by researchers around the world (e.g. Hillyard, Gillespie & Littig, 2010; Buckley, Pitt, Norton, & Owens, 2010; Meltzer & Thornton, 2011; Smith & Sodano, 2011; Samsudin et al., 2016). Based on several references (e.g. Prince, 2004), instructional methods that actively engage students in the learning process are generally defined as active learning (Samsudin et al., 2016). In physics education only presenting the available scientific information to the students and making them gain the problem solving skills that are far away from the daily life will not be enough to prepare students for the future. Students should be able to use their physics knowledge in the daily life and should be able to make sense of physical events that directly affect their lives. In this context, active learning techniques that put students into the centre should be used in physics education. One of the active learning technique is Case-Based Learning. Case-Based Learning environments are designed in such a way that the students are actively involved in changing their misconceptions and in enhancing their conceptual understanding. The essence of the method of Case-Based Learning lies in carrying events or problems that students may encounter in their everyday lives into the classroom setting. This technique provides students with the opportunity to explore, question, discuss and share, thus fostering an active learning experience. Herreid (1994) has reported that Case-Based Learning (CBL) has been used in medicine, law and school affairs since the 1800's but was not fully embraced until the 1950's when it started gaining importance.

The CBL approach is undertaken to offer students the chance to learn a subject or a skill and to engage in practicing what they have learned. Case stories are generally in written form but they can apply to visual events as well. The method is mostly used in the approach of teaching through discovery and having students develop conceptual behavior (Demirel, 1999; Açıkgöz Ün, 2003; Özkan & Azar, 2005). This approach encourages students to inquire about events and reach a conclusion as a result of their analysis (Herreid, 1994). A good case story allows students in class to discuss events that they may have encountered in the real world but have not been made clear to them, and gives them the opportunity to arrive at some conclusion (Johnson and Purvis, 1987:118; Ünal Sümen, 2013).

Cases may be taken exactly from real life. These may be called already existing case stories. Each already existing case story may be taken from sources such as newspapers, scientific books and journals, scientific studies, libraries, the Internet, television and radio broadcasts, events taking place in our own daily lives, films, videos and other similar sources taken from real life.

If cases suitable for achieving learning gains cannot be found, an imaginary scenario may be drawn up in line with the teaching activity planned by the teacher in order to give the student a feeling of the real experience. Even if cases already exist or have been rewritten, they may still not be in their entirety suitable in terms of educational criteria (Herreid, 2005; Alacapınar, 2008:10). If the teacher uses a real-life situation and the event that will be shared presents a hazard for the people involved, it is then necessary to change the place, time and persons in the story. There are as many benefits in a teacher's recounting an imaginary situation as there are in the teacher's describing a real-life situation. This is because when the student is confronted with the event in CBL, he/she will act in accordance with the form of behavior that had previously been learned and thus easily cope with the problem (Ergün & Özdaş, 1997; CoHE, 2003; Horzum & Alper, 2006). The student who learns through sample cases is able to use the knowledge gained in daily life and is more capable of easily interpreting them (Thomas, O’Connor, Albert, Boutain & Brandt, 2001; Horzum & Alper, 2006).

According to Horzum & Alper (2006), the Case-Based Learning method, with its application of learned concepts and principles, helps to fill in the gap between theory and practice in learning environments. The Case-Based Learning method further removes itself from traditional Science/Physics education, and targets teaching students how to adopt positive attitudes toward learning, become aware of their own cognitive levels and develop competencies in areas such as scientific literacy (Çakır, Berberoğlu & Alparslan, 2001; Özkan & Azar, 2005). Making use of case-based learning methods in science classes causes students to develop an increased interest in the course and by facilitating the daily-life applications of the knowledge learned in class, allows students to explore different solutions to problems, thereby improving their practical intelligence (Çakır et al., 2001; Özkan & Azar, 2005).

Case-Based Science Education

Conant (1957) was the first to use CBL in science education. Conant made use of stories about science in his own classes. (Çakır, Berberoğlu, Alpsan & Uysal, 2006). While the application of Case-Based Learning (CBL) provides a powerful pivot point in physics education, there are very few studies on Case-Based Learning (CBL) in physics education. In a previous study by Özkan & Azar (2005), the researchers made a comparison of Case-based Learning and traditional instruction in terms of the achievements of 9th grade students in the physics unit on "Heat and Temperature," their ability to learn concepts, and their attitudes toward the course. When the literature was reviewed, no study related to Case-Based Learning (CBL) in physics education was encountered.

Among the most frequently posed questions of students during their physics education is related to how they can use the knowledge they gain in school in their daily lives. In the light of the related literature (e.g., Sudzina, 1997; Wellington, 2006; Kreber, Klampfleitner, McCune, Bayne & Knottenbelt, 2007), it can be said that the case-based learning method is one of the best ways of answering students' questions in this context. It is through this method that students will be able to satisfy their curiosity by having their questions answered.

Student Misconceptions on the Subject of Energy

Work and energy are topics about which students have alternative concepts in their minds and thus frequently form misconceptions (Bahar, Öztürk & Ateş, 2002; Aydın & Balım, 2005; Aydoğmuş, 2008; Cerit Berber, 2008; Hırça, 2008; Şahin, İpek & Ayas, 2008; Arslan & Kurnaz, 2009; Ayvacı & Devecioğlu, 2009; Emepue & Soyibo, 2009; Uzunkavak, 2009; Treagust et al., 2010; Ergin, 2011; Torosluoğlu Çekiç, 2011; Chabalengula, Sanders & Mumba, 2012; Erduran Avcı, Kara & Karaca, 2012). It is observed that students find work in the context of physics difficult to understand and that they confuse the concept of work in real life with the idea of work in the physical sense of the word (Watts,1983; Solomon, 1982,1983; Diakidoy, Kendeou & Ioannides, 2003; Torosluoğlu Çekiç, 2011; Kurnaz; 2011). It has been found that students are conceptually challenged by the notion of conserving mechanical energy (Gülçiçek & Yağbasan 2004a; Gülçiçek & Yağbasan 2004b). In a study by Yürümezoğlu and Çökelez (2010), it was reported that students had difficulty with understanding forms of energy in the context of energy conversion. Various studies have been undertaken to eliminate the various alternative concepts students have about the topics of work and energy (Akbulut, Şahin & Çepni, 2013; Erduran Avcı et al., 2012; Torosluoğlu Çekiç, 2011; Cerit Berber & Sarı, 2009a, 2009b; Cerit Berber, 2008; Hırça, 2008; Forde, 2003). When these studies are reviewed however, it can be seen that these topics have not been taught with Case-Based Learning applications.

One of the basic concepts taught in the 2013 Secondary School Physics Course Program is energy. The concept of energy is one of the most difficult concepts that students conceptualize (Stylianidou, Ormerod & Ogborn, 2002; Yürümezoğlu, Ayaz & Çökelez, 2009: p.56). Many concepts in physics education are associated with each other and these relationships are usually expressed with formulas. The relationship between work and energy, for example, is expressed with the formula W=ΔE and when explaining this relationship, it is said that, "work exerted is equal to the change in energy." It is an undeniable fact that students of physics generally find it difficult to make associations between concepts. Moreover, in forming relationships between concepts, students may also form misconceptions. Some alternative concepts and misconceptions were encountered in a review of the literature in the field (e.g., Akbulut et al., 2013; Erduran Avcı et al., 2012; Yağbasan et al., 2005).

Two-tier tests are used in many Turkish and international studies to enable an in-depth review of student concepts (e.g., Karataş, Köse & Coştu, 2003; Çalık, 2006; İpek, 2007; Er Nas, 2008; Treagust & Chandrasegaran, 2007; Şahin & Çepni, 2011). In the relevant literature, however, it is seen that there are only a limited number of studies that use the two-tier test in the context of the subject of "Energy" (e.g., Hırça, 2008). In this context, to determine the conceptual understanding and conceptual achievement of students with respect to the concepts in the unit on "Energy" (related to Mechanical Energy), developing a two-tier test will be a contribution to the literature.

Ayas et al. (2007) have reported that in teaching concepts, both traditional instruction and new approaches are put to use but since many concepts cannot be definitely described verbally, the methods of traditional instruction fall short in teaching concepts, whereas new methods introduce the student to examples of concepts for which descriptive qualities can be found and the student can be led into making a generalization from examples.

In this context, it can be said that since the application of concepts and principles learned in Case-Based Learning method brings students face-to-face with real life, the method fills the gap between theory and application in learning environments and for this reason, stands out as an alternative teaching method that may be used in place of traditional instruction when teaching concepts.

Research Focus

In the light of the relevant literature, our aim in this study of 9th grade students exposed to both Case-Based Learning and traditional instruction was to determine whether there were significant differences between the effects of these two methods on the students' conceptual understanding and conceptual achievement. The study sought answers to the following sub-problem:

How did the conceptual understanding of students in the Case-Based Learning group and the traditional instruction group change from pre- to post-instruction?