Effectiveness of technological design on elementary student teachers' understanding of air resistance, gravity, terminal velocity and acceleration: Model parachute race activity

It was seen that there was an increased in elementary student teachers’ levels of understanding the concepts of Air Resistance (See. Figure 2), Terminal Velocity (See. Figure 6) and Acceleration (See. Figure 8). This result shows agreement with the result of the study by Roth (2001) related to student learning while creating technological designs. According to Roth (2001), creating technological designs contributes to students’ learning of science concepts in various ways. A similar result is seen in the review study carried out by Sidawi (2009) aimed at achieving science teaching through technological design activities. Creating technological design in science teaching contributes to the development of conceptual knowledge of students as well as their procedural knowledge.

The change occurring in elementary student teachers’ levels of understanding of the concept of acceleration is indicated in Figure 8. The number of groups displaying improvement in understanding related to the concept of acceleration is higher than the number of groups displaying improvement in understanding related to concepts of Air Resistance and Terminal Velocity. This shows that prospective teachers included in the sample learnt the concept of acceleration better than other concepts in the process of “Model Parachute” and “Model Parachute Race”. It is thought that there are 2 factors behind this result. The first one is about works performed in the designing process, and the second one is about trial flights performed in order to test endurance of prepared model parachutes. It is seen that, in drawings and interview conducted with elementary student teachers’ representing Group 6 before the application (see. Figure 9), the elementary student teachers’ defined the concept of Acceleration incorrectly. The same elementary student teachers’ defined the concept of Acceleration correctly in the interviews conducted after the application. It can be said that correct definition of the concept of Acceleration by elementary student teachers’ comes from research activities performed with group mates. It can be concluded that Group 6 reached the correct definition while applying the concept of Acceleration in the “Model Parachute” design. Since elementary student teachers’ cannot directly observe Acceleration only during trials performed with group mates in the designing process without doing research about the concept of Acceleration, they cannot reach the concept of Acceleration correctly. The change occurring in the concept of Acceleration can be reached only through research about the concept and transfer of obtained information into design. It was reported in a study conducted by Brandt (1998) that a technological design process enabled students to transfer theoretical information they obtained into application. Barak & Zadok (2009) concluded that students were responsible for their own learning within the process of technological design, and they had to do research apart from simple trial-and-error activities while creating a design in order to put forward a successful product. It was stated that doing research about the topic contributed to concretization of abstract concepts (Roth, 2001; ITEA, 2003, 2007).

Upon examining the chart of change in understanding level related to the concept of Gravity (see. Figure 4), it will be seen that, unlike changes in understanding levels related to Air Resistance (See. Figure 2), Terminal Velocity (See. Figure 6) and Acceleration (See. Figure 8), the number of groups displaying a development in understanding level related to the concept of gravity was less than the number of groups showing no development in the understanding level. This result may be interpreted in a corollary that elementary student teachers’ did not achieve an adequate learning of the concept of Gravity. It is seen that elementary student teachers’ did research about concepts such as Air Resistance, Terminal Velocity and Acceleration within the process of designing a "Model Parachute", but did not do any research about the concept of gravity. It was seen that elementary student teachers’ performed direct trials in order to see the impact of gravity on endurance of parachute without doing any research. Although these trials contributes to the use of the most appropriate gravity in the designs elementary student teachers’ made, this caused them to fail to produce an adequate explanation for the concept of gravity in interviews conducted after the application. Barak & Zadok (2009) reported that having students create designs without giving any theoretical information about concepts relevant to the design or having students conduct research about this topic causes inadequate learning of concepts. It was revealed in this study that the process in which designs were made in conjunction with theoretical information generated more successful products. Sidawi (2009) also argued that students should go through training about concepts related to the design in order for a successful technological design to be created. It was concluded in the present study that there was lower increase in understanding level related to the concept of Gravity, about which no research was done, in comparison to increases in understanding levels related to Air Resistance, Terminal Velocity and Acceleration about which a wide range of research was done. Thus, it was determined that students should go through training about concepts within a designing process. It was concluded that elementary student teachers’ learnt science concepts better during technological design process. However, understanding the level concerning science concepts pertained to the design is directly associated with the method applied in the designing process. The fact that there was not an adequate increase in the levels of understanding of the concepts in the application in which no formal education was provided or no research was done brought about the conclusion that creating a technological design was not adequate by itself in the teaching of concepts. Accordingly, it is thought that if a technological design process is supported with theoretical information, desired change will occur in levels of understanding of the science concepts.