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Asia-Pacific Forum on Science Learning and Teaching, Volume 19, Issue 1, Article 14 (Jun., 2018) |
The action research technique and the grounded theory, which are one of the qualitative research techniques, were used in this study. For the purpose of the study, an attempt was made to create a mental model for the learning process of the heat concept. To this end, it is aimed to provide an analytical generalization, which is defined as the attempt to reach certain results or hypotheses with a limited number of participants or sources of information (Altunışık et al., 2002).
Problem Based Learning (PBL) groups were formed in the study with the participation of voluntary sophomore students studying to become physics teachers at a public university. The purposive sampling method was employed to achieve this. One of the inclusion criteria was not taking a course including subjects on thermodynamics during their university education. So, students didn't take the same course in thermodynamics. They have different backgrounds on heat concept. It's important to have rich data.
The same problem was given to the groups and the PBL process was run for five weeks. A student (Nickname: Ekin) in one of these groups was selected to examine throughout the process. The selection made in terms of providing richest data. Opinions of the selected student related to the heat concept were examined throughout the five-week PBL process.
A problem which "warming up problems of a ski resort in a mounted position" was given to the PBL group. The group members tried to solve the problem for five weeks. First of all, they distinguished the problem to four sub-problems. They set a week to solve each sub-problem. Accordingly, they examined the advantages and disadvantages of geographical location, examining the heat production source, insulation techniques, and the heating system, respectively.
They started to study by investigating factors such as the average temperature, the highest and lowest temperatures, wind and pressure of the region in the first week. At the same time, they studied the concepts of temperature and pressure. In the second week, they examined the energy sources in the region. Ekin particularly emphasized geothermal energy. At the same time, she tried to learn the concept of heat. She focused on the relationship between heat and thermal energy. Participants studied insulation techniques in the third week. Meanwhile, they focused on the concept of "heat loss". In the last week, he tried to synthesize their thoughts on the planning heating system. They made suggestions for the problem by making presentations in the fifth week.
Throughout the process, they researched concepts such as temperature, pressure, heat, thermal energy, heat loss by using the internet and printed publications. They compared the contradictory information they had obtained and questioned the reliability of this information. For this reason, Ekin changed her thoughts on the concepts throughout the process.
Semi-structured interviews were held with the student throughout the PBL process. The purpose of these interviews is to reveal the knowledge and opinions of the student about the heat concept and other related concepts. To this end, direct questions about heat concept were asked to the student, as well as indirect questions about heat transfer, change of state, and expansion were asked to reveal her opinions about the heat concept. Five interviews were held with the student throughout the process in total. In the first interview, general opinions of the student on heat were revealed. In the second interview, opinions of the student on the heat concept were revealed through the example of heat transfer additively. In the third interview, the example of expansion was added. In the fourth interview, the example of change of state was added. The fifth interview included a comprehensive summary of all opinions of the student on the heat concept directly and based on various examples.
The data collection process continued throughout the teaching process carried out using the PBL method. Table I shows the PBL process and at which stage of the process the data was collected.
Table I. Activity implementation schedule related to the conceptual data obtained from Ekin
Week Date Time Process Briefing Week
24th Feb.
16:30
Briefing
25th Feb.
13:30
Analysis of Problem Session
First Week
2nd March
14:00
First Interview
3rd March
16:30
Sub-Problem Session
4th March
13:30
Sub-Problem Session
Second Week
5th March
12:30
Second Interview
10th March
16:30
Sub-Problem Session
11th March
13:30
Sub-Problem Session
Third Week
15th March
13:30
Sub-Problem Session
16:00
Third Interview
18th March
13:30
Sub-Problem Session
Fourth Week
22nd March
09:30
Fourth Interview
13:30
Sub-Problem Session
25th Mart
13:30
Sub-Problem Session
Fifth Week
29th Mart
09:30
Fifth Interview
13:30
Final Session
1st April
13:30
Presentations
2nd April
16:30
Assessment
As shown in Table I, the process took about five weeks to complete. Session dates and hours were decided by consulting with the participants. Weekly interview dates and hours were decided by consulting with Ekin.
The interviews with the student were transcribed and then the data was examined using the content analysis method. Propositions asserted by the student related to the heat concept were individually extracted from dialogs and each proposition was taken as a code. The related codes were assigned to the same group.
Firstly, interviews with the student were examined individually. Then, all interviews were examined holistically. The following stages were followed to this end.
- Transcribing the interviews.
- Obtaining codes using the transcription of the interviews.
- Assigning codes to groups.
- Detecting relations between codes and code groups.
- Interpreting the interviews by using excerpts from the interviews.
- Determining relations between opinions of the student.
- Detecting the process of conceptual change.
When analyzing the interviews, the codes repeated concurrently or consecutively during the interview process were determined in order to detect relations between codes and code groups. Then, excerpts from the dialog at that time were examined to find whether there was a logical connection between these codes. Relations were determined using this approach. An example to interview excerpts used to determine codes can be seen below:
Interviewer: Q = m.c.ΔT. What do you understand from this equation? What does it mean? So, what value do you calculate using Q = m.c.ΔT?
Ekin: It is actually heated change. (Q09) For example, ΔT is what we use to calculate the thermal energy between the initial state and the final state by the final temperature minus the initial temperature.
Interviewer: So, you think that it is heated change. Is that correct?
Ekin: Yes, heat change. (Q09) Since we calculate it, for instance, ice must have heat at the beginning. (Q04) Because we subtract the initial value from the final value.
(First Interview)The codes in this excerpt are Q09 (There is a concept called heat change) and Q04 (Matter stores heat / Matter has heat). Using this approach, it was examined whether or not there was a logical relation between consecutively detected codes. Repeat frequency and the persistence level of the student's opinion related to a given code were also considered. Persistence level is determined using her precision of words. Charts were created using these variables. In these charts, other codes were proportioned according to the most frequently repeated code.
After determining relations between codes, all relations in the interview were examined taking temporal order as well and a general interpretation was made for each interview. Resulting relations were assessed by categories and generally based on temporal change. It was thus described how the conceptual construct in the mind of the student changed throughout the process.
