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Asia-Pacific Forum on Science Learning and Teaching, Volume 19, Issue 2, Article 19 (Dec., 2018) |
The examination of the pretest and posttest answer sheets has resulted in the description of pretest and posttest problem-solving strategy by 23 students. The results are shown in table-1.
Table 1. Percentage of students using knowledge sketching strategy
problem-solving strategy
Percentage of students using problem solving strategies (n=23)
Pretest
Posttest
Known-Asked (Traditional)
82.61
0.00
Knowledge Sketching Strategy
0.00
65.22
Combination of both Strategies
17.39
34.78
It can be seen from table-1 above, that generally students still use the known-asked strategy in solving the problem of multi-concept physics (pretest). In fact according to Amin, Abdullah & Malago (2018) that the known-asked strategy is only able to solve the problems of mono-concept physics. As a result, the students got scores below which was expected. The pretest scores are shown in table 2 including the posttest scores.
It can be seen from the table 2 below that there is an increase in the score after using knowledge sketching strategy in the completion of multi-concept physics problem. the average increases in the score from the pretest to the posttest is 4.04. These results reinforce the belief that the knowledge sketching strategy is one of the best strategies used in solving multi-concept physics problems compared to the known-asked strategy.
Table 2. Results of examination of pretest and posttest answer sheets
ni
Score
∆x=(xf-xi)
Pretest (xi)
Postest (xf)
1
6
9
3
2
6
9
3
3
5
10
5
4
5
10
5
5
5
6
1
6
5
7
2
7
4
10
6
8
4
8
4
9
4
9
5
10
4
10
6
11
4
8
4
12
3
8
5
13
3
8
5
14
3
10
7
15
3
8
5
16
3
7
4
17
3
6
3
18
3
7
4
19
3
5
2
20
2
7
5
21
2
4
2
22
2
5
3
23
1
5
4
Average
3.61
7.65
4.04
Std
1.30
1.85
1.50
Why is there an increase in multi-concept completion scores after the students being taught a "knowledge sketching strategy"? This question can be answered by looking at two aspects: (1) aspect of the material content of the problem, and (2) aspect of the problem-solving strategy. Judging from the aspect of the material content about pretest and posttest, the actual content of the material consists of three interrelated concepts. According to the writer's experience in teaching physics, that the problem of multi-concept physics requires the thinking stages of imaginative thinking, analytical thinking, and synthesis thinking. Therefore, for the students who are rarely trained to use these three skills, it will be difficult to solve the problem of multi-concept physics. As an illustration, the following description will show the problem of pretest used in this study.
What do the student think after reading about the pretest? It is possible that they imagine about the process of the events of the problem. The process is: (1) when the bullet will hit the ball, (2) the moment after the bullet has penetrated the ball, and (3) when the ball and the bullet fall to the ground. Any student who has studied the concepts contained in the matter will be able to imagine the events in the problem. This process is called imagining events in the problem. However, the problem is the students cannot describe the equations depicted in their mind, especially for problems that contain complex events. Why is that? Because they are rarely trained formulate the equations based on the events that are reflected in their mind. The ability to formulate an equation based on the events depicted in the human mind is called imaginative thinking. In general the ability of imaginative thinking is the ability to actualize ideas or images in mind. Therefore, the main goal of physics teaching is to train imaginative thinking ability. Eisntein once argued that imagination is more important than knowledge (Hadzigeorgiou & Fotinos, 2007).
How to train students to think imaginatively in physics? The writer has explained in above section that one good way to train students thinking imaginatively is by using knowledge sketching strategy as a strategy in teaching physics. There are three stages in this strategy, but the core stage is the " sketching". It is a way of translating the problem language into simple sketches or drawings (Abdullah, 2014). The process of this stage is somewhat similar to a painter who is able to pour ideas that are reflected in his mind in the form of paintings or sketches. Therefore, students who study physics should be treated as a painter. They should be trained to pour ideas in the form of design, narration, images, or prototype.
The physics problems is a set of concepts that make up the unit of knowledge. For example, the pretest problem above consists of the concept of momentum, free fall motion and parabolic motion. These three concepts form a unit of knowledge called "ballistic test knowledge". In solving the pretest problem, the first thing students do is to read the problem. At the time of reading the problem, the students try to connect the concepts that have been known. In the process of connection, an imaginary image about the events mentioned in the problem will be formed in the head. In this condition, there are students who are already able to pour the image in the form of equations to obtain the answers. Students like this are classified as "genius" students. However, most students find it difficult to formulate the image in the head. For that, they need to be assisted through sketches before making the formulation. That is, the image formed in the head, first poured in the form of sketches. As for the pretest problem above, the sketch is as in the picture-2 below.
Figure-2. Stages in translating verbal language into sketch form
As can be seen in the figure-2, there are three sketch results were made. The first sketch describes the momentum occurrences before the collision, the second sketch of the momentum event after the collision, and the third sketch is parabolic motions of both ball and bullet. The interesting thing about these three sketches is that it clearly shows the relationship between one sketch and another. This relationship is determined by the velocity variables after the collision. This process is not found in the "known-asked" strategy.
Viewed from the aspect of teaching, if the knowledge sketching strategy is made as part of the physics teaching process, then there are many advantages that can be obtained by the students, one of the most important is "students are trained to think imaginatively". That is, through the teaching of knowledge sketching strategy, students will be trained to organize their knowledge and be able to pour the ideas in the form of sketches. This condition can only be done if the human mind has previous knowledge saved. It is commonly found in an expert's knowledge rather than a beginner's knowledge (National Research Council, 1999), and an expert knowledge has a deeper understanding than a beginner (Simon, 2001).
However, this view can not be used as a limitation that only applies to an expert, but the organization of knowledge can also be applied to students who have had prior knowledge. The writer, therefore, assumes that the organizing of knowledge can be trained in the teaching process as long as the students who are taught have prior knowledge. If a student does not have prior knowledge of one of the concepts that are needed to solve the problem of physics, the writer believes that the student will not be able to organize his/her knowledge (Abdullah, et.al, 2013). And although the students have knowledge of all these concepts, but they are rarely trained to organize their knowledge in solving physics problems, the writer also believe that the students will have difficulty in solving the problem. This fact occurs because, in the teaching program, the curriculum is often designed in a way that makes it difficult for students to organize their knowledge (Santrock, 2010).
On the basis of the views of experts mentioned above, the writer believes that to form expert knowledge on the students it is necessary to do the teaching that emphasizes the process of imaginative thinking. The process of imagination is very important in science learning. Even Smolucha & Smolucha (1986) suggested that imagination is a higher mental function because it consciously directs the thinking process. The same opinion is stated by Liang.et.al (2012) that imaginative thinking is the basis to cultivate creative thinking. Thus, the writer believes that the sketching stage in the knowledge sketching strategy is very good to be used in teaching physics to train the ability of imaginative thinking.
In addition to the sketching stage, the formulating stage is the stage of analysis thinking process. Why? Because through the sketches of the problems described, then the students' minds will form the process of assimilation. In this process, there is an incubation period of knowledge, the period in which there is an adjustment between the concept it possesses with the concepts contained in each sketch. If more than one sketch is made, there is a process of knowledge orientation based on the sketches .
The last step is the process of combining the equations that have been formulated at the formulating stage. This process requires mathematical skills to relate one equation to another to find answers. Therefore, in this last stage, the aspect that students need is the ability of mathematical operations.
