Students’ Conceptual Changes on the Air Pressure Learning Using Predict-Observe-Explain Strategy

The concept of air-having pressure needs to be understood by students so that they can understand natural phenomena related to the air concept. The characteristic of the abstract concept of air having pressure leads students to misconceptions. The purpose of this study is to analyze changes in students' conceptions of the air-having pressure concept by using the POE strategy. The research method used was a pre-experiment with one group pretestposttest design. Pretest and posttest questions were given to students using the five-level diagnostic test instrument with a total of three questions. The ability to predict-test and the ability to observe-test were performed with four questions on each test. The participants of this study consisted of 31 fifth grade students in the even semester. The categorization of conception change is divided into five patterns: construction, revision, static, disorientation, and complementation. Based on the analysis, revision had the highest percentage followed by construction. The conclusion is that the POE strategy can help students in understanding the concept of air-having pressure so that there was a change from misconception to understanding scientific concepts.

[67] In fact, by knowing and understanding the characteristics of air, students will find various explanations about natural phenomena that occur in everyday life.
The concept of air and its characteristics are studied by students in the content of science lessons. The implementation of the science learning process requires a direct involvement of students so that students get the actual natural facts about a concept. However, it seems that the teaching of science in Indonesia still has not optimally helped students to comprehend science in everyday life. This is based on the results of the 2018 Program for International Student Assessment (PISA, 2019) which shows that Indonesia is ranked 9th from the bottom (71) in the science category. The assessment is based on students' understanding of science and scientific inquiry. Understanding of science is one of the important skills in 21st-century education and elementary students must be taught about this (Turiman, Omar, Daud, & Osman, 2012). In addition to understanding concepts scientifically, in the process, scientific understanding helps students practice inventive thinking from analyzing to solving problems in life (Abdullah & Osman, 2010).
Understanding the concept of air having pressure needs to be had by students so that they can apply and reason the concept correctly so that they can understand natural conditions. learning instilling an understanding of concepts becomes a very challenging thing because in the process students often experience misunderstandings of concepts. Elementary school students experience many misconceptions about basic science concepts because both texts and teachers are inadequate in dealing with their misconceptions (Eaton, Anderson, & Smith, 2005;Pine, Messer, & John, 2001) and personal experiences also influence student conceptions (González, 2010). The possibility of the emergence of misconceptions in students should be a concern for teachers because once a misunderstanding has formed, then it will continue and it is difficult to change it (Bayuni, Sopandi, & Sujana, 2018;Kala, Yaman, & Ayas, 2013;Thompson, 2006). To avoid misconceptions, in science learning especially learning about the nature of air having pressure, it is necessary to apply a learning strategy where students are actively involved physically and mentally to see and reason (Yamtinah et al., 2019). One learning strategy that can overcome misconceptions iss through the application of the Prediction, Observation, and Explanation (POE) strategy (Chang et al., 2012;Karamustafaoğlu & Mamlok-Naaman, 2015). This strategy provides opportunities for students to produce conceptual knowledge and develop reasoning abilities that can be applied to problemsolving (Chang et al., 2012). POE emphasizes experiment-based learning where students are trained to predict, conduct experiments and explain their findings (Karamustafaoğlu & Mamlok-Naaman, 2015). POE can be applied in the process of learning science because learning science is a direct activity that requires students to be involved in the scientific process through practice (Conn, 2014;Jasdilla, Fitria, & Sopandi, 2019). The practice of science requires the use of technology to experiment, assess, and evaluate ideas and theories. Three main steps must be implemented in the learning process of POE (Chang et al., 2012;Kala et al., 2013).
These stages are prediction, observation, and explanation.
There have been many studies using POE strategies to improve students' understanding of concepts at various levels of education (Akpınar, 2014;Hsu, Tsai, & Liang, 2011;Kibirige, Osodo, & Tlala, 2014;Özdemir, Bağ, & Bilen, 2011;Wu & Tsai, 2005). Furthermore, for the concept of air, there have been several studies regarding the application of concepts about the behavior or characteristics of air (Chao, Chiu, DeJaegher, & Pan, 2016;Wiebe & Stinner, 2010). These studies have been carried out at the level of secondary education and above. At the early childhood level, there have also been studies on the introduction of air characteristics using POE strategies (ChiLiang, 2011). However, it seems that there has been no study on the application of POE strategies to the concept of air at the elementary school level. Thus, this study aims to determine the conceptual changes students have about air pressure in elementary school. The concept of air is one of the important concepts for students in understanding the characteristics of the nature of air. Therefore, the current study was conducted to answer the research question regarding whether there was a conceptual change in students about the concept of air having pressure using the POE strategy.

METHOD
This research was conducted in the even semester in 2019. This study aimed to determine changes in students' conceptions of the concept of air having pressure by using the POE strategy. This study used an experimental method with one group pretest-posttest design. This experimental method was used as an exploratory experiment to analyze changes in the pretest and expected posttest results of the participants after receiving experimental interventions (Ary, Jacobs, & Sorensen, 2010;Gall, Gall, & Borg, 2010).
The study participants consisted of 31-fifth grade students in one of the elementary schools located in Bandung city. The test instrument used for data collection is an instrument designed by the researchers themselves. It was designed to determine students' conceptual changes through experiment-based learning. This instrument also tested students' ability to predict and the ability to observe. The instrument for pretest and posttest was in the form of a five-level diagnostic test. The first level was choices of answers, the second level was a level of trust in choices at the first level, the third level was an explanation of the choices of answers at the first level, the fourth level was a picture illustration to prove the explanation at the third level, and the fifth level was a level of confidence in the illustration of the picture. This test was chosen to produce a detailed explanation of what participants actually thought about the concepts learned either before or after the treatment was given (Anam, 2019).
Meanwhile, the predicting instrument consisted of 2 questions with multiple choice answers and 2 questions with open answers. The instrument for the observation process consisted of 4 questions related to the experimental process. The test instruments were validated by experts who were lecturers in the Environmental Education Oriented Science Education Practicum course. Validity was done in connection with the adequacy, structure, language, and relevance of the instrument. The validation process by experts was not based on the score but rather direct advice on what should be improved on the test instrument.

Research Procedure
The procedures of the study began by deliberately selecting one primary school. The researchers intentionally established an experiment-based POE strategy in the teaching process about the concept of air having pressure. The learning process lasted for 90 minutes with 2 different experiments. Teaching began with a pre-test on 31 students. Next, the core teaching using the POE strategy started with 4 stages. The first stage was predicting in which the students were given a prediction sheet before experimenting. The second stage was observing during the trial period. The first experiment was about the concept of water not spilling in an upside-down bottle. The second experiment was about quail eggs that could enter the bottle even though the hole was smaller than the size of the quail. During the probationary period, the students were given observation sheets to fill out. The third stage was asking the students to explain their findings during the trial period to their friends. Finally, the post-test teaching was given to all students who participate in this teaching.
Research data were obtained from the results of the pretest, prediction test, observation test, and posttest. The results of the four tests were scored and then coded according to the students' conception level category. The students' conceptions were categorized into six levels (Anam, Widodo, Sopandi, & Wu, 2019), namely: Scientific Conception (SC), Almost Scientific

Conception (ASC), Lack of Confidence (LC) Lack of Knowledge (LK) Misconception (MSC) and
Have No Conception (HNC). Next, to determine the category of conceptual change, students' answer codes in the pre-test and post-test were matched into the category of existing concept change patterns. The following table is a table for determining patterns of change in students' conceptions based on those formulated by Anam (2019).

RESULTS
Research data to get a picture of changes in the conception of students on-air having pressure were obtained from several tests including the pretest, prediction test, observation test, and posttest.

Profile of Students' Initial Conceptions
Preliminary tests were conducted to determine the condition of students' initial conceptions regarding the concept of air having pressure. In this test, question no 1 is related to the concept of air pressure compared to water pressure. Then problem number 2 is related to air pressure at higher temperatures and air pressure at lower temperatures. Then, question no. 3 is about the natural phenomenon of air pollution related to the concept of air pressure. The following is the profile of students' initial conceptions obtained through the analysis of student answers in the pretest.

Profile of the Ability to Predict
In the first stage of POE, students learned to predict a situation that would occur related to the application of certain concepts (Muna, 2017). Also, in this section, students were also expected to provide explanations or reasons regarding the allegations given. The results of the analysis regarding the ability to predict students are shown in Figure 2.

Profile of Students' Ability to Observe
The second stage is the observation where students were invited to conduct experiments to test the correctness of predictions that students conveyed before. This observation phase assistsed students in developing one of the basic scientific skills (Muna, 2017;Wardani, Widodo, & Priyani, 2009

Profile of Students' Final Conceptions
Knowing the extent to which students' conceptions are related to a scientific concept is an important thing to do (Yamtinah et al., 2019). ). If there is a misconception in students, the teacher will be able to provide follow-up to develop a fully scientific concept (Gomez-Zwiep, 2008). Students' conceptions can be identified through the provision of tests, one of which is the use of five-tier diagnostic tests. After administering the treatment using the POE strategy, the students' posttest results on the concept of air having pressure were obtained as shown in Figure 3.

Patterns of Change in Students' Conceptions
Changes in conceptions that occured in each of these students certainly varied according to the initial concept they had and the ability of each student understanding. The category of level changes in students' conceptions and the number of percentages can be seen in  Table 3. categories of change in students' conceptions

Profile of Students' Initial Conceptions
When going to discuss science topics for the first time the teacher cannot assume that students know nothing about these science topics because students have developed their assumptions about science topics even before learning begins (Taber, 2016 Based on Figure 1, there is a tendency that students' conceptions of air having pressure are between levels of ASC, LK, MSC, and HNC. There are no students at the ASC level In questions no. 1 and 2, while in question no. 3, about 6% of students are at the ASC level. LK level appears in all three questions with the same percentage in questions no. 1 and 2. Then, the MSC level appears most dominant in questions no. 1 and 3. These data indicate that the initial conceptions that many students have are in the category of misconceptions. Their conceptions are categorized as misconceptions because students provide answers that do not fit scientific concepts, and at questions of confidence level, students respond confidently to their answers. In the answers, students believe more in the role of objects in the experiment, not in the role of pressure from the air. Many sources contribute to misunderstandings, ranging from personal experiences, family, friends, analogies, media, teachers, and textbooks (Bayraktar, 2009;Moodley & Gaigher, 2019). Student misunderstandings will affect the way students learn new scientific knowledge that plays an important role in further learning and becomes a barrier in gaining true knowledge (Özmen, 2004). In addition, based on the data in Figure 1, it is also found that there are still students who do not have a concept of air pressure.
By knowing the state of students 'initial conceptions, teachers can consider more meaningful learning arrangements to build scientific concepts on students' thinking (Kala et al., 2013;Malleus, Kikas, & Marken, 2017). Figure 2 shows that the ability of students to predict the concept of air having pressure is at the LK and HNC levels only. LK level dominates most students. This means that students' conception of air having pressure is still lacking so students are less able to predict what will happen about the experiments that will be conducted. In addition, there are some students who are at the NHC level, meaning the answers to predictions made are not in accordance with the concept of air. In question no. 1, the question asked is about the condition of the water in the bottle if the position of the bottle is reversed. For this answer, most students predict that the water in the bottle will spill, then in the explanation section, no student has mentioned the presence of air pressure.

Profile of the Ability to Predict
The ability to predict arises as a result of the initial conception possessed by students.
Justification at the prediction stage provides opportunities for students to classify and justify their own pre-conceptions (Hsu et al., 2011). This knowledge is important to know because it can give teachers information about students' difficulties in achieving new concepts and choosing strategies that effectively help students to overcome difficulties (Yang, Noh, Scharmann, & Kang, 2014).

Profile of the Ability to Observe
After doing the observations on the experiments, students' understanding of the concept of air pressure has improved from the concept they have before. Based on table 2 it appears that the ability of students to observe the concept of air having pressure is at 3 levels, namely SC, ASC, and LK. In experiments 1 and 2, the highest level category of students is at the ASC level.
By conducting experiments, students can understand the concept of air pressure by directly seeing how the work of the air pressure. By conducting experiments, it is hoped that there will be a process of reconstructing new concepts from the initial concepts students have. Next, students make repeated observations, make measurements, analyze, and interpret data which then ends by drawing conclusions that are in accordance with scientific concepts.
Through this activity, students carry out experimental learning activities through concrete activities and can find their own answers to the problems they face so that learning activities become meaningful to students (Ariyati, 2018;Wardani et al., 2009). When observing activities are carried out by students, teachers should not be careless in presenting situations. In POE strategies, teachers need to present situations where students will feel stimulated and challenged and can discuss with peers about the ideas they have obtained (Adebayo & Olufunke, 2015).

Profile of Students' Final Conceptions
Based on Figure 3, it can be observed that after learning is given using the POE strategy, the students' conception level has improved with the emergence of the SC level. This SC level indicates that students can achieve scientific conceptions in air pressure lessons. In questions no. 1 and no. 2, most of the students' answers are at the ASC level which shows that most students have almost understood the scientific concept of air pressure, although not as a whole. Then, for question number 3, most of the students' answers are at the LK level. This means that there is still little information that can be understood by students regarding the concept of air having a pressure associated with natural phenomena in everyday life. On the question of understanding related to this natural phenomenon, there are still students who experience misconceptions even though the percentage is smaller than the pretest. One of the factors causing misconceptions is the lack of teachers 'understanding of the basic concepts of science that they teach, resulting in misinformation on students' understanding (Atwood, Christopher, Combs, & Roland, 2010;Yates & Marek, 2013). Another factor can be caused by the textbooks used by them (Arntzen, Lokke, Lokke, & Eilertsen, 2010;Yamtinah et al., 2019). In addition, misconceptions can occur because students tend to memorize concepts rather than understand concepts so that when connected with the real world they will have difficulties (Banda, Mumba, Chabalengula, & Mbewe, 2011). Students must continue to be guided and facilitated by teachers to learn actively and find concepts so that misconceptions can be corrected into scientific concepts (Gomez-Zwiep, 2008;Radzi, Abdullah, & Muruthi, 2017).
Through POE, students' misconceptions that are detected at the initial test stage and predictions can gradually be transformed into scientific concepts. Furthermore, POE presents learning by direct observation. thus, the concept will be formed completely and last longer.
After gaining scientific experience, students learn to explain the connection between their experiments and their scientific concepts. Thus, students not only gain knowledge but also reason knowledge.

Changing Patterns of Students' Conceptions
Before learning begins, students actually already have their own initial understanding/ conception about the various problems of natural events (Yamtinah et al., 2019). The conception is obtained by students from the results of their interaction with nature or with people around or from reading sources they have read. In responding to new information obtained, students can maintain their initial conception substantially (no change) or replace it due to inconsistencies (Hewson, 2011). Table 3 shows that the majority of students make improvements regarding their understanding of the concept of air having pressure. This concept is, in fact, a concept that is close to the daily lives of students. Therefore, the concept of air is important to teach to elementary students (ChiLiang, 2011). The concept of air is taught in elementary schools through lessons in the form of objects and their characteristics, but this concept is rarely discussed in depth by the teacher.
POE strategies can be used to correct misunderstandings of concepts to improve students' understanding of concepts in the learning process (Hsu et al., 2011;Kearney, 2004;Kibirige et al., 2014). In its implementation, the teacher's role is to explore students' understanding by asking them to carry out three main tasks, namely predicting, observing, and explaining. The advantage of this POE strategy is that students are invited to make predictions about a concept to be learned and students are actively involved in the search for scientific truth through experimental activities. This research shows that direct experiments can help students understand the concept of air pressure in an easy way.

CONCLUSION
Understanding of scientific concepts is important for students to have. This is because correct understanding can help students create solutions to problems in their lives either through an idea or work. Based on the results of the intervention using the POE strategy, most students could understand the scientific concept of air pressure. This strategy helped to minimize the occurrence of misunderstandings in students' minds. In teaching practice, students were interested in experiment-based teaching. They could see how natural phenomena that occur out there can be witnessed in the classroom. With the results obtained, it can be concluded that this POE strategy could be applied to help students understand other science concepts.
This research is expected to contribute to efforts to understand science concepts in elementary school students through the implementation of the POE strategy so that it can be the basis for the future implementation of the POE strategy.