Student teachers’ levels of understanding and model of understanding about Newton's laws of motion

Sample

The sample for this study consisted of 45 elementary student teachers in an education faculty in the Black Sea Region of Turkey. The sample was randomly selected from second year student teachers undertaking an introductory physics course. A few parts of these students have already studied Newton’s Laws of Motion in physics lessons in high school; but the other students took this subject for the first time in their physics courses at university.

Instrument and Data Collection Process

An achievement test, developed by the researchers, about Newton’s Laws of Motion composed of 12 open-ended questions or items, was used as a data-gathering instrument. In the first part of the test, an everyday example or sample case was presented to students. They were asked questions about the ‘sample case’ that probed their ability to explain the sample case (Item A), determine the physics law explaining the sample case (Item B) and provide an additional sample case about related law (Item C). Overall, three questions were asked about Newton’s three laws of motion, totaling nine questions in all. In the second part of the test, participants were asked three questions about defining Newton’s laws of motion (Item D). We introduce the test items below:

Problem (1)

Please describe the movement of a child on a scooter while the scooter is bumping against a barrier.

Which laws of physics can explain the movement of the child?

There are many more applications of this law that you have explained. Could you give one more example?

Please explain this law.

Problem (2)

Please consider your experiences about pushing a car that has a dead engine and explain the relation between the cars’ acceleration according to the forces applied as |F₁|>|F₂|>|F₃|.

Which physics’ law can be used to explain the variance of acceleration values of the car pushed?

Please give an example referring to this law.

How can we explain this law?

Problem (3)

Please describe the movement of a person who has fired a rifle.

Which law of physics can explain this fact?

Please give another example confirming the presence of this law.

Define this law.

One researcher completed the data collection during introductory physics courses. Students were given 40 minute to complete the test and they were encouraged to freely express their thoughts. They were assured that it was not an examination and their answers were not to be used in order to evaluate their academic levels.

Pilot Study

In order to test the data collection instrument, a pilot study was conducted with 30 student teachers enrolled in an introductory physics course. The data provided by the pilot study was not included in the actual study. The students’ papers showed that the items introduced above were understood by participants and provided data that could be analysed to answer the research question. Furthermore, the research questions and the achievement test were discussed by a group of researchers to confirm the validity of the test.

Data analysis

Student responses were analyzed in two ways. The first identified the student level of understanding and the second identified the student model of understanding. The analysis of understanding level is a suitable analysis method, which gives a general view of the academic level of participants about each question on an achievement test. On the other hand, the student model of understanding helps to analyze a student’ answers to all questions about a subject, in other words, helps to analyze students’ answers individually. In that way, one can find a link between the student’s knowledge about a subject. In other words, one can reach some clues about student’s mental model. Because mental models are used to construct new knowledge (Vosniadou and Brewer, 1992), it is important to reach some understanding about them. As there are mental models composed by the students behind the meaningful learning (Duit and Glynn, 1996 in Ünal and Ergin, 2006), putting forward the participants’ general achievement about any subject is not only enough for arranging the instruction and education activities.

Student Level of Understanding

Data obtained from the instrument was analyzed to understand levels of understanding as suggested by Abraham et al. (1992) and adapted by Coştu (2002) (see Table 1).

Table 1 Categories Used to Determine Student Level of Understanding and Their Characteristics

Level of Understanding	Criteria for Scoring
[0] No response (NR)	Leaving blank Answering “I don’t know” Answering “I don’t understand”
[1] No Understanding (NU)	Complete repetition Irrelevant answer Vague answer
[2] Incorrect Understanding (IU)	Insensible information Incorrect information
[3] Partial Understanding (PU)	Answers that include only one aspect but not all aspects of a valid answer Answers that include some aspects of a valid answer and some misunderstandings
[4] Sound Understanding (SU)	Answers that include all aspects of a valid answer

Student Model of Understanding

In the second stage of the study, student answers were analyzed according to the models shown below in Table 2. These models were adapted from the Students’ Model of Understanding in Typology of Perceived Knowledge as suggested by Saglam (2004).

Table 2. Understanding Models and their Characteristics

Model of Understanding	Characteristics
OM (Optimum Model)	Student properly defines, utilizes, applies and exemplifies any piece of theoretical knowledge.
UM (Uncreative Model)	Student properly defines, utilizes and applies any piece of theoretical knowledge but fails in exemplifying it.
TM (Theoretical Model)	Student properly determines and defines any piece of theoretical knowledge but fails in applying and exemplifying it.
PM (Practical Model)	Student properly applies and exemplifies any piece of theoretical knowledge but fails in determining and defining it.
MM (Memorizing Model)	Student properly defines any piece of theoretical knowledge as the books do but fails in utilizing, applying and exemplifying.
IM (Inappropriate Model)	Student fails defining, utilizing, applying and exemplifying any piece of theoretical knowledge.

Student answers to the four questions about each law of motion were analyzed collectively to determine the characteristics of each individual’s model of understanding. To achieve this, the characteristics of each Model of Understanding shown in Table 2 were applied to the items put to students and associated with the Level of Understanding described in Table 1. The relationships between students’ model of understanding and students’ level of understanding are shown in Table 3.

Table 3 The Relationship between Students’ Model of Understanding and Students’ Level of Understanding

Model of Understanding	Characteristics	Levels for Items (A, B, C, D)
Optimum Model (OM)	Answers to each of the 4 questions requiring explaining the sample case, determining the law, exemplifying the law and defining the law about any of Newton’s Laws of Motion are at level 3 [PU] or level 4 [SU].
Uncreative Model (UM)	Answers to each of the 3 questions requiring explaining the sample case, determining the law and defining the law about any of Newton’s Laws of Motion are at level 3 [PU] or level 4 [SU]. However, the answer for exemplifying the law question is at level 0 [NR], level 1 [NU] or level 2 [IU].
Theoretical Model (TM)	Answers to the questions requiring determining the law and defining the law about any of Newton’s Laws of Motion are at level 3 [PU] or level 4 [SU]. However, the answers for explaining the sample case and exemplifying the law questions are at level 0 [NR], level 1 [NU] or level 2 [IU].
Practical Model (PM)	Answers to the questions requiring explaining the sample case and exemplifying the law about any of Newton’s Laws of Motion are at level 3 [PU] or level 4 [SU]. However, the answers for determining the law and defining the law questions are at level 0 [NR], level 1 [NU] or level 2 [IU].
Memorizing Model (MM)	Answers to the question requiring defining the law about any of Newton’s Laws of Motion are at level 3 [PU] or level 4 [SU]. However, the answers for explaining the sample case, determining the law and exemplifying the law questions are at level 0 [NR], level 1 [NU] or level 2 [IU].
Inappropriate Model (IM)	The answers to all 4 questions requiring defining the law, explaining the sample case, determining the law and exemplifying the law about any of Newton’s Laws of Motion are at 0 [NR], level 1 [NU] or 2 [IU].

Levels of Understanding: [0]: No response; [1]: No Understanding; [2]: Incorrect Understanding; [3]: Partial Understanding; [4]: Sound Understanding

To determine the model of understanding for any given student about one of Newton’s laws of motion, their levels of understanding for each item related to that particular law of motion were examined. For example, the levels of understanding for Student A for each of the four items about Newton’s First Law of Motion were as follows: level 1 for item A; level 0 for item B; level 1 for item C and level 3 for item D. Using the matrices shown in the third column of Table 3, the model of understanding for Student A is the Memorizing Model.