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Asia-Pacific Forum
on Science Learning and Teaching, Volume 10, Issue 1, Article 6
(June, 2009) |
Analyzing the data obtained in this study, carried out to examine the prospective physics teachers understanding levels of the concepts of energy, power and force, it was determined that the level of understanding of the participants did not live up to expected standards. In other words, the data analysis showed that the participant students had difficultly defining and explaining the meaning of the concepts. It is obvious that such weaknesses of prospective teachers, who will play the leading role in the distribution of instructional activities, will adversely affect the learning of their students.
The analysis of the available data indicated that the energy, power and force definitions of the bulk of the sample did not match the scientific facts. It was noticed that the students confused the concepts of energy, power and force with each other or with the concept of force while they were trying to define them. That is, they were in the state of a true contradiction of terms. It can be assumed that the students were in the state of wrong perception about the mentioned concepts, since the concept of power relies on the concept of energy, and the concept of force is one of the fundamental concepts used while the concept of energy is being explained. On the other hand, the fact that these concepts are referred to as if they were alternatives of each other in daily life can be considered as a factor causing this situation. The similar remarks in Duit (1984), Kruger (1990) and Küçük et al.(2005) have supported these conclusions. However, as Aycan and Yumuşak (2003) mentioned, prospective physics teachers should exhibit the skill of utilizing and referring to the concepts by differentiating between them in both contexts (in scientific and daily life contexts). Analyzing the data and considering the teacher skills in pre-service education period, it can be said that the prospective physics teachers did not possess these skills or they had difficulties in demonstrating these skills. The situation is similar to the results of Trumpers study (1998) subjecting the conceptual development states of the university students about the concept of energy.
As another result of the study, it was determined that most participants were not at an intended level to state, explain, and recall measurement units. Students were expected to explain that energy and power are not quantities defined with direction and magnitude in space, whereas force is a quantity that has a direction and magnitude. Among the three concepts, the students were rather successful at explaining that the force is a vector quantity, but they still had difficulty explaining the reason. Additionally, parallel to the results of the study by Goldring and Osborne (1994), even though the students were more successful in determining the units of the concepts than they were in the other questions, they were still below the intended level. Even though they had been instructed about the units of these concepts since primary school, most of the students could not answer this question correctly. This can be evidence of not learning the related concepts and their properties correctly. According to White (1992), students care for formulas involving these concepts but they have a tendency to learn their properties superficially, although they are frequently faced with these concepts. That is, students give priority to learn the quantitative aspects of the concepts, while they hardly consider the qualitative ways. Moreover, it is known that this situation negatively affects these concepts to be learned (Goldring and Osborne, 1994; Kurnaz, 2007).
Besides the definition and properties of energy, power and force, associating skills of theoretical gains with daily life experiments of prospective physics teachers were also investigated, since there are vital relations between the related concepts and daily life experiences. While the term energy is used with no borders in daily life experiences, it has strict borders in scientific field, as McClelland (1989) noted. Students should direct daily usage starting from scientific usage (Aycan & Yumuşak, 2003). The findings of this study implied that the participants had difficulties associating the situations that they experienced with the energy, power and force concepts in a scientific manner. Almost all of the students left the question inquiring about the relationship of the three concepts and related object unanswered. This shows that students could not comprehend the state of related concepts being/not being a property of an object. The simplicity of the answer for this question suggests that this fundamental incompetence of the prospective teachers is a significant case to be examined. This situation is thought to arise from immature knowledge of the students about the concepts. Backed by available data, we could say that this is the same for the relations between movement-energy, movement-power and movement-force. By reviewing student answers, we can voice an overall failure, and we can notice that the least scientific answers were given for power out of the three concepts. The reason for the students inability to draw such relationships is because the instructional process of these concepts was implemented without qualitative inquiries. Similar results were found in Kurnazs study (2007) of first year university students.
The agreement between the results of the present study and the studies involving primary school students (Küçük et al., 2005; Hırça et al., 2008) actually implies that learning difficulties associated with the concerned concepts are valid for all age groups. Taking into account the profile of the sample of this study, it can be said that such difficulties can also be valid for teachers, as well as students, as Kruger (1990) and McClelland disclosed.
Supported by the result indicating prospective physics teachers were not at the adequate level in defining the energy, power and force concepts scientifically and their inability to state the characteristics and explain the situations in relationship to their environment, it can be suggested that the three concepts should be given in coherence (i.e. concerning the relations, restrictions, and differences between them) in an instructional situation. For instance, in a conceptual manner, the three concepts can be presented comparatively. Comparative presentations will be effective when the students have difficulties in referring inter-conceptual relations. For such an organization to be practiced, we also think that concept maps and conceptual change texts will be useful and we suggest them.
