The Effect of Argumentation-Based Learning Environments on Pre-service Science Teachers' Conceptual Understanding and Decision Making Styles

The aim of this study is to investigate the effect of making argumentation practices on the conceptual understanding level and decision making styles of pre-service science teachers on socio-scientific subject, genetically modified organisms (GMO). The sample of this study consists of 48 Pre-service science teachers studying in the 2nd grade of the science education department, Faculty of Education, in the 2018-1019 academic year. 24 of the pre-service science teachers are the experimental group and 24 of them are the control group. Case study was used in the study. In the experimental group; within the scope of 5E teaching model; with materials and animations containing Toulmin's argumentation model; the control group was processed with traditional teaching methods. Conceptual understanding levels of Pre-service science teachers, who constitute the experimental and control groups, about GMO before and after the teaching activities, were measured. As a data collection tool in the research; the open-ended question and likert type scale consisting of 12 items, which are based on GMO, based on expert opinions and have scope validity, is the Knowledge Test on Genetically Modified Products of University Students (KTGMOUS), pre-test and post-test. It was applied as a test. In addition, a five-point Likert-type "Decision-Making Styles Scale" consisting of 24 items was applied to the experimental group in the form of pre-test and posttest. Findings obtained at the end of the study are presented.


Introduction
There is a strong link between science and society. The reason for this is the development or renewal of scientific knowledge in line with the needs of society (Sadler & Zeidler, 2005b). "With the interaction of society and science, issues that concern both society and science", ie socio-scientific issues, have emerged (Sadler, 2004). Scientific developments on genetic engineering (stem cells, gene therapy, cloning) and ecology (global warming) can be given as examples (Topç u, 2008). Since they have both good and bad results as a result of their use, these issues create great dilemmas or contradictions in society, that is, these issues are seen as controversial issues in society. Along with the educational status of the people, the views related to socio-scientific issues are cultural, religious, political, etc. situations are also thought to affect. Since the contents of socio-scientific subjects are situations that can be encountered in daily life, teaching and understanding these subjects to students is also among the important objectives of their education (Albe, 2008;Kolsto, 2006;Walker & Zeidler, 2007).

Purpose and Importance of the Study
The aim of this study is to determine the effect of the argumentation process practices and the use of course materials developed on the subject on the conceptual understanding level of science Pre-service science teachers on GMO and the relationship between decision making strategies on a socio-scientific subject and field knowledge. For this, the teaching of the socio-scientific subject, GMO; Instead of traditional teaching, it was provided with the use of animations and argumentation process.
The effective socio-scientific subject culture required at every stage of life is directly related to the quality of the conceptual education to be applied to students. Therefore, the contradictions and inconsistencies in their learning must be exposed and eliminated in order for the concepts to be introduced to students to be meaningful and permanent. At this point, the biggest task belongs to the teachers. One of the most important duties of teachers in education and training is to identify any misunderstandings in students' information and to provide the necessary conceptual change (Sevim & Tarım, 2017;Sevim, 2013;Ayas, Ünal & Sevim, 2004). Therefore, regardless of the branch of the teacher, especially in socio-scientific matters, teachers should basically have an intellectual knowledge. It should not be overlooked that the current misconceptions in teachers will negatively affect the conceptual development of students. For this reason, first of all, misconceptions in teachers' pre-service education should be determined and eliminated.

Research Design
In this study, semi-experimental method with pretest-posttest control group, which is one of the experimental research models, was used. While teaching methods used in experimental and control groups are independent variables of the research, conceptual knowledge of pre-service science teachers about GMO has been determined as dependent variables of the study. Therefore, open-ended and likert-type scale was applied to the students in the experimental and control groups in order to determine and compare the effects of the teaching activities carried out on the dependent variables.

Participants of the Study
The universe of the study consists of 2nd grade students of the Department of Science Education of Universities in the Aegean Region. The sample consists of 48 Pre-service science teachers, including the experimental and control group studying in the 2nd grade of Pamukkale University Faculty of Education, Science Teaching Program.

Data Collection Tool
In the research, open-ended and likert type scales, which are specified in the following items, were used as data collection tools.

Knowledge Level Test of University Students on Genetically Modified Products
"The Knowledge Levels Test on Genetically Modified Products of University Students" is a Likert type scale consisting of a total of 18 items used by Çiftç i and Terin (2018). In order to test the reliability of the scale (questionnaire) used in the research, reliability analysis was performed with the SPSS 23 package program for the expressions used in the analyses. As a result of the analysis, Cronbach's Alpha coefficient, which gives the reliability statistics, was found 0.77. Accordingly, it can be said that the scale used in the study is quite reliable (Kalaycı, 2006: 405).

Open-Ended Questions on the Subject of GMO
An open-ended question consisting of 12 items with a scope validity, prepared by taking the opinions of experts on the subject of GMO, was used. Questions on the scale; It is prepared according to three different achievements, which are aimed at pre-service science teachers' explanation of basic concepts and conceptual relations related to biotechnology, their awareness about genetically modified organisms (GMO), and their assessment of GMO in terms of benefit and harm. While evaluating the scale questions, the answers given by Pre-service science teachers to open-ended questions were categorized in four groups according to their level of understanding. These are; full comprehension, incomplete comprehension, poor comprehension and inability to respond. An example is given to the categorization process of Pre-service science teachers' answers to open-ended questions about GMO; If the definition is made correctly, explanation-examples are correct and given directly related to the definition, the Teacher Candidate is in the level of full understanding in the question he / she answers. If the definition has been made correctly, explanation-no sample or explanation-examples have been given correctly, but the definition has not been made, the Teacher Candidate is at the level of incomplete understanding in the question he / she answered. If a different definition is made than the scientific one, or if the explanation -examples are given incorrectly, the Teacher Candidate is in the level of weak understanding in the question he answers.

Decision Making Style Scale
Decision-Making Style Scale is a five-point Likert-type scale developed by Scott and Bruce (1995) and adapted to Turkish by Taşdelen (2002). The Chronbach α test was applied for the validity and reliability test of the scale, which was analysed in five sub-dimensions as rational, intuitive, dependent, avoidance and spontaneous-decision making style. While the overall value of the test was 0.887, the lowest subscale value was seen in the "Dependent Decision Making Style" (α = 0.760).

Application Process
The teaching activities in the implementation process of the study were carried out for 4 weeks within the scope of the course "Biology II." In the experimental group, the subject of GMO was taught with argumentation practices and the animations developed within the scope of the 5E model. Information about the activities to be done before the beginning was given. The activities to be carried out in the experimental group were explained sequentially, and then the course applications were started. After the pre-test application, the argumentation process was taught in the first week and the different achievements Sample argumentation applications were made and then 5E model application process was started. At the stage of drawing attention; Concept map (containing the concepts of gene, DNA, chromosome etc.) has been applied in order to control the preliminary information.
Then, FROM DNA to PROTEIN-3D animation was watched and the missing information and concepts in the animation were discussed. To Pre-service science teachers; '' Cancer, diabetes, hereditary disease, etc. in the family, around or in itself Is there anyone with the disease? According to the responses given by the Pre-service science teachers, the answers were guided in such a way that the causes of these diseases or suggestions of solutions were directed to the answer that the genes in the organism originated. During the discovery phase, "A.1: Explains the basic concepts and conceptual relations related to biotechnology. A.2: Gains awareness of GMO. A.3: Evaluates GMO in terms of benefit and harm. "Candidates were asked to complete the relevant questions or inference sections on the activity papers by watching animations. When asked to evaluate GMO in terms of benefits and harms, in addition to animations, argumentation practices were made, and Pre-service science teachers in the computer lab were able to research and present their arguments. After each animation, explanations on gains are included in line with arguments and inferences. After all these, in the deepening stage, Pre-service science teachers were asked questions to address one of the problem situations they encounter in their daily lives, and they were provided with the information they gained about gene replacement technology and their research and thinking skills were increased. Post-test was used as an evaluation tool at the end of the course activities. To the control group; It was first applied as a pre-test. The post-test was applied by the researcher to the Pre-service science teachers after teaching the subject with traditional teaching methods.

Findings
In this section, the data obtained from the measurement tools used in the research are presented.

Pre-service Science Teachers' Data Obtained From "Knowledge Levels Test on Genetically Modified Products of University Students"(KTGMOU)
In this study, the results obtained from the "KTGMOU" scale applied to Pre-service science teachers as well as open-ended questions prepared to determine the knowledge levels of Pre-service science teachers about GMO products are given in Table 2, Table 3, Table 4 and Table 5. It is presented. The scale consists of 18 questions, the benefits of GMOs, loss, etc. production in Turkey. It deals with the issues. This scale was applied within the scope of pre-test and post-test. According to the results in Table 2; In the pre-test, there was no statistically significant difference at the level of 05 between the experimental and control group Pre-service science teachers' level of knowledge regarding the subject of "Genetically Modified Products" (t =, 051; p>, 05). According to the results in Table-3; In the post-test, there was a statistically significant difference at the level of 05 between the knowledge levels of the pre-service and control group Pre-service science teachers on the subject of "Genetically Modified Products" (t =, 325; p <, 05). This situation is in favor of the experimental group. While the average score of the experimental group Pre-service science teachers was 2.68, the average score of the control group Pre-service science teachers was 2.56. In this case, it was observed that the Pre-service science teachers were more successful than the pre-control teachers. According to the results in Table 4; There was a statistically significant difference at the level of 05 between the pre-test and post-test genetically modified products of the experimental group Pre-service science teachers at level 05 (t = 0.045; p <, 05). This difference is in favour of the post-test. While the pre-test averages of the pre-test teachers were 2.45, the post-test averages increased to 2.68. Based on all these analyses, argumentation applications within the scope of 5E model; it was concluded that Pre-service science teachers had an effect on "KTGMOU". According to the results in Table 5; There was no statistically significant difference at the level of 05 between the pre-test and post-test genetically modified products of experimental group pre-service science teachers at level 05 (t = 0.911; p>, 05).

Data from Open-Ended Questions
Open-ended questions; Prepared to measure the level of knowledge of pre-service science teachers about the acquisitions of "basic concepts about biotechnology, awareness of GMO, benefits and harms of GMO". It was applied twice before and after the application and consists of 12 questions in total. An example of the analysis of open-ended questions and the findings obtained from the scale are presented in Table 6, Table 7 and Table 8.
For example, the analysis of the answers to a question asked for Acquisition 1 is presented below. A sample answer was given for each category. Therefore, the analysis of open-ended questions was done in this way.
A.1: Explains the basic concepts and conceptual relations related to biotechnology.
Question 3: Briefly describe GMO. Describe your definition.
Complete understanding: Pre-service science teachers are at full understanding if they answer the question as follows.
"The concept of 'Genetically Modified Organism' is used for plants, animals, or microorganisms whose specific characteristics are altered by transferring genes from one species or a species other than it. For example; Recombinant plasmid DNA can be produced by the non-insulin-producing bacterial cell when the gene responsible for producing the hormone insulin in humans is cut off by the restriction enzyme and added to the plasmid DNA from the bacterial cell with the enzyme ligase." Missing Information: Pre-service science teachers are in the level of incomprehension if they answer the question as follows.
"It is the process of transferring a gene to a living being from a species other than its own." Weak Understanding: If Pre-service science teachers answer the question as below, they are at a poor understanding level.
"Deviations from their real state as a result of the genetics of foods being played." Not Responding: Pre-service science teachers are at the level of unresponsive if they leave the question blank.   As seen in Table-6; It was observed that almost none of the experimental and control group Pre-service science teachers could answer the questions covering the acquisition of A.1 before the application at full comprehension level. (For the second question, both groups answered 8.3%; for the third question, experimental group Pre-service science teachers answered 8.3%, and control group Pre-service science teachers answered 12.5%). It has been observed that the Pre-service science teachers' comprehension level rates reached up to 100% after the application (70.8% for the first and third questions, 91.6% for the second questions, 100% for the fourth questions). As a result, it is in question that almost all levels of poor comprehension and non-responsiveness reach complete and incomplete comprehension levels after application. (Some questions are 4.1%). On the other hand, there is no change in the levels of comprehension of the control group Pre-service science teachers after the application, and there is a decrease in the levels of full comprehension in questions two and three. In general terms, it was observed that they respond at incomplete and weak comprehension levels.
At the same time, when the answers given by Pre-service science teachers are examined;  As seen in Table 7; Experimental group Pre-service science teachers were not able to answer the questions covering the A.3 acquisition at the level of full comprehension; It was observed that the Teacher Candidate teachers responded at 4.1% and 16.6% at full comprehension level. It has been observed that the experimental group Pre-service science teachers' understanding level has reached up to 87.5% after the application. (58.3% for the first question, 87.5% for the second question and 25% for the third question). As a result; it was found that the level of inability to respond completely was eliminated, and the levels of weak comprehension decreased and reached levels of incomplete comprehension and full comprehension. It was observed that the Pre-service science teachers were not able to answer the full comprehension level in question number ten after the application, 12.5% in the eleven question and 25% in the twelve question. Based on the findings, it was observed that the conceptual perception levels of the Pre-service science teachers were higher than the control group. At the same time, when the answers given by Pre-service science teachers are examined;  As seen in Table 8; Experimental group Pre-service science teachers were not able to answer the questions covering A.3 acquisition at the level of full comprehension; It was observed that the Teacher Candidate teachers responded at 4.1% and 16.6% at full comprehension level. It has been observed that the experimental group Pre-service science teachers' understanding level has reached up to 87.5% after application. (58.3% for the first question, 87.5% for the second question and 25% for the third question). As a result; it was found that the level of inability to respond completely was eliminated, and the levels of weak comprehension decreased and reached the levels of incomplete comprehension and full comprehension. It was observed that the Pre-service science teachers were not able to answer the full comprehension level in question number 10, and 12.5% in the eleven question and 25% in the twelve question. Based on the findings, it was observed that the conceptual perception levels of the Pre-service science teachers were higher than the control group. At the same time, when the answers given by pre-service science teachers are examined;

KG-4 teacher candidate, "How do GMO products affect human health before the application? Explain your answer with examples. "While answering the question numbered ten," Human health may have a negative effect in a good way. After the application, he responded, "It affects human health in a bad way. In this example; We can see that the CG-4 teacher candidate focused only on the bad aspects of GMO after the application. While the KG-19 teacher candidate cannot answer the question before the application, after the application; "It is both beneficial and harmful. It is beneficial in terms of developments in the field of health. However, it has a harmful effect due to the side effects it shows even as a result of its use in the field of health. "Reached the level of full understanding.
Considering the examples and values in the table above, it can be said that teaching with argumentation practice within the scope of 5E model is very effective in developing the conceptual understanding levels of pre-service science teachers about genetically modified organisms

Findings Regarding Pre-service Science Teachers' Decision Making Styles
This scale was applied to investigate the effects of argumentation practices, which is the sub-problem of the study, on the decision-making styles of experimental group pre-service science teachers. The data obtained from this scale applied to pre-and post-test pre-test teachers were presented in Table 9, Table 10, Table 11 and Table  12. According to the results in Table 9; When the Rational Decision-Making Style is examined; While the pre-test Pre-service science teachers had an average of 4.18, the post-test increased to 4.95, and there was a positive change. A statistically significant difference was found (f = 46,204, p = 0,0001). After the application, it was determined that Pre-service science teachers showed improvement in rational decision making styles. When the Heuristic Decision-Making Style is examined according to the results in Table 10; In the pre-test results, Pre-service science teachers had an average of 3.83, post-test averages decreased to 2.77 and a X X statistically significant difference was found (f = 0.212, p = 0.0001). It was found that Pre-service science teachers showed negative development in heuristic decision making styles after the application. When the Dependent Decision-Making Style is examined according to the results in Table-11; While the pre-test teachers had an average of 3.60, the pre-test averages decreased to 2.58 and a statistically significant difference was found (f = 0.062, p = 0.0001). After the application, it was found that Pre-service science teachers showed negative development in dependent decision making styles. When Avoidance Decision-Making Style is examined according to the results in Table-12; While pre-test Pre-service science teachers had 2.78 averages, post-test averages decreased to 1.78 and a statistically significant difference was found (f = 2.325, p = 0.0001). After the application, it was found that Pre-service science teachers showed negative development in avoidance decision-making style. When the Spontaneous-Instant Decision-Making Style is examined according to the data in Table 13; In the pre-test results, Pre-service science teachers had an average of 3.50, post-test averages decreased to 1.47 and a statistically significant difference was found (f = 5.556, p = 0.0001). After the application, it was found that Pre-service science teachers showed negative development of spontaneous-instant decision making style. Before starting the teaching activities, it was observed that the average of each decision making styles of the experimental group Pre-service science teachers was close to each other. When the pre-test and post-test results were examined, it was observed that the pre-test Pre-service science teachers switched from intuitive, dependent, avoidance and spontaneous decision making styles to rational decision making style. Considering the examples and the values in the table above, it can be said that teaching with argumentation-based course material is very effective not only in improving the conceptual understanding levels of the Pre-service science teachers about GMO, but also in developing decision-making styles.

Discussion, Results and Suggestions
In this chapter; Based on the findings given in the previous section, the resulting results are discussed and X X X X presented. When the pre-test results of "Knowledge Levels Test on Genetically Modified Products of University Students" were examined, there was no statistically significant difference at the level of .05 between the experimental and control group Pre-service science teachers' knowledge levels (t =, 051; p>, 05 p = 0.116). After the application, the test average of the pre-service science teachers increased from 2.45 to 2.68. There was a statistically significant difference between the pre-test and post-test results at level .05 (t = 0.045; p <, 05 p = 0.0001). This difference is in favour of the post-test. After the application with traditional teaching methods, it was found out that the pre-test average of the Pre-service science teachers decreased from 2.53 to 2.11 in the post-test. It was observed that there was no statistically significant difference at the level of 05 between the pre-test and post-test results of the control group Pre-service science teachers (t = 0.911; p>, 05 p = 0.546). As a result, argumentation applications within the scope of 5E model; It can be said that Pre-service science teachers are largely successful in increasing their knowledge level about GMO products since active participation in the lesson, discovering information and creating a scientific discussion environment enables them to construct the information. Similar results were found in similar studies on argumentation-based teaching (Acar, 2008;Akyüz, 2018).
According to the results obtained from the tests and interviews applied to Pre-service science teachers, in the study conducted by Akyüz with pre-service science teachers, it was concluded that the Pre-service science teachers' knowledge levels in GMO-related concepts were insufficient before the applications. In addition, according to the pre-test results, pre-service science teachers mix GMO, hormonal food and chemical products with each other. Similar results are observed in this study. It has been concluded that learning environments created based on argumentation technique have an impact on Pre-service science teachers' participation in discussions with argument data and reasons, and their conceptual understanding. In addition to that, when the field-literature is examined, Celep (2015), who is working on subjects other than GMO, also has a higher understanding of the concepts of gases in the experimental group students studying in the argumentation-based interrogatory education model. and misconceptions about the subject. It was determined to be less statistically. In the study conducted by Aydeniz and Doğan (2016) with Pre-service science teachers on chemical dissolution, it was concluded that the experimental group students were significantly more successful than the control group in the applied test results and also in the final exam. Nussbaum and Sinatra (2003), in their study of 41 high school students, addressed the issue of Newton's law of gravity in two groups as experimental and control groups. Considering the results of the 22-item multiple choice basic physics knowledge measurement test used as a data collection tool; It was concluded that the students of the experimental group, where they conduct argumentation-based teaching, focus on the important aspects of the problems compared to the control group students, and that they have more superiority in increasing the conceptual relationships. Chen and She (2012) focused on seven subjects in the science of physics in their work with eighth grade students (seventy-four consisting of 150 people in the experimental group and seventy-six in the control group). As the method, argumentation-based learning was used in the experimental group and traditional method was used in the control group. In this study, the concept and argumentation tests on the subject were applied as pre-test and post-test. After the applications they did with the experimental group, it was concluded that there were significant advances in the conceptual change of the experimental group students compared to the control group students. In addition, it was concluded that the students of the experimental group included in the argumentation process answered the concepts asked afterwards more accurately than before the discussion. In the study conducted by Acar (2008) with 125 pre-service science teachers, argumentation-based teaching practices on physics subjects were made. Acar used "Argumentation skills and conceptual knowledge tests" as a data collection tool in his study and reached the conclusion that the targeted concepts of teacher candidates in physics subjects that are the subject of the study have been developed.
When the analysis of open-ended questions was analysed, it was observed that almost none of the experimental and control group Pre-service science teachers were able to answer questions covering the acquisition of A.1 "explains the basic concepts and conceptual relations related to biotechnology." It has been observed that the experimental group Pre-service science teachers' comprehension levels reach up to 100% after the application. If we touch on the changes in some questions; In the first and third questions, respectively, "Briefly define biotechnology and briefly describe your definition. What is the expansion of GMO? and describe GMO briefly, explain your definition. "The level of weak understanding is completely eliminated. In the fourth question, in which there is no pre-test teacher candidate who can answer full comprehension level, "List most of the GMO products that have been applied successfully." The reason they reached 100% full comprehension level is that the animations organized are both in the health and food sector and the Pre-service science teachers in many areas during the argumentation process. they do research. As a result, in the general sense, in questions covering A.1, Pre-service science teachers' weak comprehension and non-response levels reach almost complete and incomplete comprehension levels after the application. On the other hand, the control group Pre-service science teachers did not observe any change in the level of comprehension after the application, and in the questions number two and three, "Briefly describe the genetic engineering and briefly explain your definition. What is the expansion of GMO? and define GMO briefly, explain your definition. "There is a decrease in the levels of full understanding.
It was observed that the Pre-service science teachers of the control group responded to the questions in general incomplete and weak comprehension levels. In the fourth question, in which there is no pre-test teacher candidate who can answer full comprehension level, "List most of the GMO products that are successfully applied." and lack of room for questioning and still being influenced by the media. In a similar study, this situation was mentioned. In the study conducted by Koçyiğit (2015), it was determined that the pre-service science teachers' attitudes towards GMO and their insufficient knowledge levels were not influenced by gender and age factors, and it was concluded that one of the important reasons for this was the biased publications made by the written or visual media used as a source of information.
It was observed that the vast majority of the pre-service and control group Pre-service science teachers could not answer the questions covering the acquisition of A.2 "Explains the basic concepts and conceptual relations related to biotechnology". (It was observed that the pre-service and control group Pre-service science teachers responded at a full understanding level in the ratio of 4.1% to 29.2%). It was observed that most of the experimental group Pre-service science teachers' weak comprehension and unresponsiveness levels were eliminated and they reached full and incomplete comprehension levels. (45.8% for the fifth question, 100% for the sixth question, 95.8% for the seven and eighth question, and 87.5% for the ninth question). If we touch on the changes in some questions; In the fifth question, "Can consumption of GD foods destroy human genes? Explain your choice for reasons. "The poor understanding level of pre-test teachers, which was 62.5% in the pre-test, decreased to 33.3% in the post-test. This change is below desired. The mistakes of pre-service science teachers about whether the products consumed are related to human genes or not cannot be eliminated. In addition, it was determined that all of the pre-service Pre-service science teachers were a biotechnological process in the brewing process included in the sixth question, and they could make an accurate explanation, grasp and explain the differences between hormonal and GMO products, and have an idea about why GMO products are produced. On the other hand, it was observed that the control group Pre-service science teachers did not change the level of comprehension except for the question number nine after the application, but they responded in general incomplete and weak comprehension levels. In the eighth question, the control group Pre-service science teachers' weak comprehension levels decreased from 64% to 16.6, but it was concluded that they understood that hormonal and GMO products were different from each other, but because they could not make sufficient explanation, they responded at the level of incomplete understanding. In general terms, it was observed that Pre-service science teachers of the control group did not reach sufficient levels of understanding in explaining the concept relations related to biotechnology.
Experimental group Pre-service science teachers could not answer the questions that cover the acquisition of A.3 "Evaluates GMO in terms of benefit and harm." It was observed that the Teacher Candidate teachers responded at 4.1% and 16.6% at full comprehension level. It has been observed that the experimental group Pre-service science teachers' understanding level has reached up to 87.5% after the application. (58.3% for the tenth question, 87.5% for the eleventh question and 25% for the twelfth question). As a result; it was found that the level of inability to respond completely was eliminated, and the levels of weak comprehension decreased and reached levels of incomplete comprehension and full comprehension. It was observed that the Pre-service science teachers were not able to answer the full comprehension level in question number ten after the application, 12.5% in the eleven question and 25% in the twelve question. Based on the findings, it was observed that the conceptual perception levels of the Pre-service science teachers were higher than the control group. If we touch on the changes in some questions; In the tenth question in the pre-test, pre-test Pre-service science teachers asked "How do GMO products affect human health? Explain your answer with examples. "It is at the level of weak understanding by 75%. In other words, they only mentioned the negative effects in the question. In the last test, this rate decreased to 12.5%. It has been observed that students who have a complete and incomplete comprehension level talk about the use of GMO in the treatment of diseases as well as its side effects and the negative effects of its use in the food sector as a result of developments in the health sector. In the control group, it was observed that the level of weak understanding increased from 58.3% to 87.5% in the post-test application. It was observed that there was an increase in the opinions of the control group Pre-service science teachers that the use of GMO is only harmful to human health. In relation to the tenth question, only 25% of the Pre-service science teachers in both groups were able to make sufficient explanation by addressing both the benefits and harms of the two in question number 12, which addresses their views on the benefits or harms of GMO. In addition, it was observed that 58.3% of the experimental group Pre-service science teachers were at the level of incomplete understanding of 41.7% of the control group Pre-service science teachers. In other words, they think that it is both beneficial and harmful, but they could not make sufficient explanation.
It is thought that the pre-service science teachers in both groups prior to the application were lacking in their knowledge of GMO, and that they were influenced by the media or the environment they lived in. However, in the post-application post-test, after the increase in the knowledge level of the Pre-service science teachers about GMO, the opinions of GMOs about the benefits and harms of the GMO; It was observed that they first determined the area of use and then made possible inferences. While specifying the areas of use, they explained their useful and harmful aspects quite clearly, not only in the food sector but also in the field of health, as in the preliminary tests. This means that the Pre-service science teachers' teachers benefit from the animations during the applications, they conduct research by following the scientific research process effectively in the argumentation process, and compete their arguments; it is clear evidence that it eliminates information gaps and negative attitudes and that the level of conceptual understanding of GMO is improving.
In this study, Pre-service science teachers were asked to decide on the benefits and harms of GMO. Before starting the teaching activities, the experimental group Pre-service science teachers whose rational, intuitive, dependent, avoidance, spontaneous-decision making averages are close to each other; Looking at the test results after applying the teaching activities, while positive change was observed in the rational decision making style; Negative changes have been observed in intuitive, dependent, avoidance and spontaneous decision-making styles. Looking at these results; argumentation practices revealed that Pre-service science teachers adopt rational decision-making style in the decision-making process, that is, they evaluate the alternatives and make decisions by making researches. In this study; As argumentation practices provide the opportunity for scientific discussion and providing information from multiple sources, as in the results in the literature, Pre-service science teachers' knowledge levels about GMO increased and their decision-making skills improved rationally.
Many studies have shown that the study of students' argumentation on sociological issues improves their decision making skills (Kortland, 1996;Nicaloau et al., 2009;Ratcliffe 1996;Sadler & Zeidler, 2005). For example; As a result of the study conducted by Sadler and Zeidler (2005), it was concluded that the students' rational reasoning rate was higher. n the study of Kardaş (2013), it was aimed that the students should carry out the unit "Let's Travel the World of Living Things" within the scope of science and technology lesson with Argumentation-Oriented Teaching activities; investigated the effect on decision making skills. As a result of this experimental study with the students attending the fifth grade, the experimental group showed that the decision-making skills of the students improved. Also; the study of Dori, Tal and Tsaushu in 2003, it came to the conclusion that the argumentation method in science teaching improved students' thinking skills in the decision-making process.
In this section, some suggestions are presented based on the results of the research reached in the current study and summarized in the previous section.
• If this study can be carried out for a long period of time in different gains, better results can be obtained.
• If the argumentation process is applied on different samples, the sample can work more efficiently because it dominates the process.
• In this way, a study can be conducted with students of different age groups. Thus, the effects of the argumentation process will also be revealed longitudinally.
• Comparative studies can be carried out by preparing activities using different approaches or methods than argumentation. Thus, the most appropriate method or approach can be determined.