• Journal of The Korean Association For Science Education
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• v.29 no.1
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• pp.22-42
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• 2009

The purpose of the case study is to understand changes in the teaching practices of two secondary science teachers during the span of their careers. To investigate changes in teaching practices, this study focuses on changes in the science teachers' practical principles based on Elbaz's practical knowledge. The biographical approach was adopted because teachers' voices are a valuable source to understand their professional development. In-depth interviews and classroom observations were conducted for two science teachers with seven years' and ten years' teaching experience. The major findings are as follows: First, participants' teaching practices changed through interaction with three factors, critical experiences that have stirred changes in teaching practice, teacher's reflection on teaching, and various experiences to make specific teaching practice changes. Second, three different change aspects of practical principles were revealed; reinforcement of existing practical principles, replacing old practical principles with new one, and generation of new practical principles.

• Journal of The Korean Association For Science Education
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• v.17 no.4
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• pp.435-450
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• 1997

The status of facilities, management for the experiment, practices, teaching methods in middle schools have been investigated. The present status and reasonable management of the middle school science education have been grasped from the questionaires. To do this 125 secondary science teachers, 1,745 students and 70 principals of schools in Korea are administered questionaires of Science Education Reserch Institute of Kyungpook National University(1996). The results of this study are as follows : The reasonable management for experiments and practices of science education were scanty in the middle school around the urban and rural school owing to the shortage of facilities and equipments, crowded class, excessive class works for teacher, excessive contents of present textbooks and insufficiency of the administrative supports etc. The current teaching method of middle school science has emphasized knowledge. This fact does not satisfy the objective of learning due to lack of the teaching method. Desirable directions for the improvement of present status of middle school science education were proposed in this paper

• Journal of Plant Biotechnology
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• v.48 no.1
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• pp.44-53
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• 2021

The present work aims to study the induction of somatic embryogenesis in cork oak (Quercus suber L.) from immature zygotic embryos and young apical leaves obtained from 2-month-old seedlings through acorn germination on sterilized peat. The immature zygotic embryos were grown for 1 month on the mineral solution of MS in the presence of 4.52 µM 2,4-D and 30 g/L sucrose. They were then transferred to the same mineral solution with no added growth regulators. In the third subculture, yellow somatic embryos, characterized by two voluminous cotyledons, were differentiated from the radicle of the immature zygotic embryos. The induction of somatic embryogenesis in young leaves required a series of transfers on different culture media containing 30 g/L sucrose and 100 mg/L myo-inositol. Secondary or recurrent somatic embryogenesis occurred within the immature somatic embryo radicles after 1 month of culture on growth regulator-free medium containing WPM macronutrients, MS micronutrients, and vitamins.

• Journal of The Korean Association For Science Education
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• v.22 no.3
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• pp.560-570
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• 2002

This study was focused on whether secondary science teachers have consistent, integrative scheme on the definition of atmospheric pressure and phenomena caused by air pressure. We had made questionnaire and let 94 science teachers answer. We sorted the responses according to their major, school and compared them with the description in textbooks. The result can be summarized into three findings. First of all, teachers whose major is chemistry have strong tendency to understand that atmospheric pressure is caused by molecular motion though it, in textbooks, is defined as the pressure by weight of air mass. The half of respondents believed that decreasing of atmospheric pressure in high altitude is due to molecular motions, while most textbook says decrease in the weight of air mass. Secondly, many science textbooks show that air mass expands, rises, becomes less dense and the pressure of atmosphere becomes low when it receives heat. So, most of respondents explained low pressure is formed by lower density. Thirdly, they answered that they just teach the phenomena of air pressure by using the textbooks which mainly deal with the present state rather than a principle. In conclusion, the science textbooks should present the exact description and consolidated structures of those concepts to prevent students from having misconceptions on air pressure. In addition, training program for science teachers would be necessary to reconsider and explore the natural phenomena in various viewpoints.

• Journal of The Korean Association For Science Education
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• v.36 no.5
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• pp.769-781
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• 2016

This study investigated the interactions among the PCK components of pre-service secondary chemistry teachers considered in the processes of making written test items individually and in small groups. The processes of making written test items individually for 8 pre-service teachers was studied through the think-aloud method. The analysis of the results revealed that the 'assessment in science education' of the five PCK components was most frequently used in making test items. 'Curriculum for science education,' 'subject matter knowledge,' and 'students' were also frequently used although fewer than the previous component. However, 'instructional strategies and instruction for science education' was hardly used. The integrations between two or three components with various types were frequently found. However, integrations among four to five components were not found. The processes of making written test items in two small groups consisting of four pre-service teachers were observed. The analysis of the results revealed that the PCK components used in small groups were similar to those in the individual processes. However, 'curriculum for science education' was less frequently used, and the numbers of subcategories used at a relatively high frequency increased from other four components in small groups. In the aspects of integration, the proportion of the integrations between two components decreased and that for three components increased compared with those in the individual processes. The integrations among four or five components were also newly found. However, the integrations of 'curriculum for science education' with the other components were less frequently found. The integrations of 'instructional strategies and instruction for science education' with other components were still hardly found.

• Journal of The Korean Association For Science Education
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• v.37 no.4
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• pp.693-703
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• 2017

In this study, 37 elementary, middle, and high school science teachers attending graduate schools of education were surveyed about their thoughts about the difficulty of teaching science units and teaching methods to teach these units to students. After experiencing the activity of making new teaching tools using scratch, we tried to confirm the development of TPACK among the teachers. Through the questionnaire survey for elementary, secondary, and high school science teachers, we selected the unit of Planetary Movement of the Solar System as a unit that is difficult for teachers to teach. We gave them the experience of instruction on tool making process for implementing a planetary operation model using scratch. Then, based on the questionnaires and class presentations, we analyzed the change of awareness about technology introduction and the development of their TPACK. As a result, most of the teachers showed changes of perceptions related to TK, TCK, TPK; the use of programming for creating teaching materials enhances teachers' understanding of the teaching contents; the teachers were convinced that students would develop the ability to construct models that fit observational phenomena; they thought that there would be a positive educational effect in the positive domain.

• 대한공업교육학회지
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• v.36 no.2
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• pp.219-238
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• 2011

The purpose of this study was to analyze the industrial education items in the teacher recruitment examination for secondary school and make a better proposal. To achieve the purpose, all the industrial education items, which had taken an examination for ten times from the school year 2002 to the most recent year 2011, were analyzed. The results of this study were as follows; First, the number and score ratio of industrial education items had been increased quarterly from the school year 2002 to 2011, but had same sharing in all subjects and fixed since the school year 2010. Second, as the industrial education items had been increased quarterly, they were taken from more various subcategory of industrial education. Recently, the industrial education items on "complex domain" including two more subcategory of industrial education were increased. Third, the industrial education items with science education items was compared from the school year 2009 to 2011. The items on PCK(Pedagogical Content Knowledge) had been increased in the industrial education but the proportion of PCK was lower than science education.

• Journal of The Korean Association For Science Education
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• v.29 no.4
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• pp.450-462
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• 2009

In this study, we investigated the influences of teaching practices upon pre-service secondary teachers' perceptions on the learning cycle by their understanding of it. Surveys on their understanding and perceptions of the learning cycle were administered to 37 seniors at the department of chemistry education in two colleges of education before teaching practices, and the survey for perceptions of the learning cycle was given to them after teaching practices. In addition, we selected seven pre-service teachers with decreased perceptions after teaching practices, and interviewed them thoroughly to investigate the factors influencing the decrease of their perceptions. The results revealed that the degree of pre-service secondary teachers' understanding of the learning cycle was not high, but their perceptions on the advantage/disadvantage of the learning cycle, their willingness to implement it, and the external aids influencing implementation were relatively positive before they practiced teaching. However, their positive perceptions more or less decreased after entering the teaching practice and the degree of decrease for those having a higher understanding of the learning cycle was larger than those having a lower understanding of it. The results of the interviews suggested the factors of pre-service teachers, students, curriculum and outside conditions as the causes of the decrease. Educational implications of these findings are discussed.

• Journal of the Korean Chemical Society
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• v.52 no.1
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• pp.84-95
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• 2008

In this study, preconceptions held by chemistry major secondary school science teachers were searched in relation to explanations of water evaporation phenomena with phase equilibrium diagrams. 25 chemistry major science teachers were selected to complete questionnaires developed in this study and 6 among of them were selected to participate in follow-up interviews. Among these, 10 participants were selected for an evaluation of the change of their preconceptions through lessons developed in this study. From the results, it was found that many teachers believed that the phase equilibrium diagram could not explain water evaporation phenomena. They also thought that there was no relation between vapor pressure and the vertical axis of the phase equilibrium diagram. However, after the lessons in earth science, they recognized that the vapor pressure curve of the phase equilibrium diagram could be explained by adopting a saturated vapor curve. Because they had known the process of application the conceptions of saturated situation, nonsaturated situation, process of equilibrium movement in saturated vapor curve. They could understand natural phenomena such as evaporation with the phase equilibrium diagram through a change in their conceptions as guided from science lessons integrating earth science and chemistry.

• Journal of the Korean earth science society
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• v.29 no.4
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• pp.352-362
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• 2008

This study explored pre-service teachers' mental models about eclipse phenomena to investigate their understandings on the earth science concept needed f3r an integrated approach. We conducted in-depth interviews with two different contexts on 30 secondary and 36 primary pre-service teachers participants, and analyzed phenomenological primitives (p-prims) and facets of causal explanations about eclipses. Based on this study, we identified four different levels of mental models about eclipses. Four mental models were categorized as (1) Screening model, (2) Orbital plane model, (3) Hybrid model, and (4) Shadow cast model. Screening model is a flawed mental model, orbital plane model is an incomplete correct mental model, and shadow cast model is a scientifically correct mental model. Hybrid model, composite of two or more mental models, use multiple mental models simultaneously. Orbital plane model was the most widespread mental model in secondary pre-service teachers group, whereas screening model was used frequently in primary group. It was found that the level of mental model could be determined by the level of facet and p-prims. We confirmed context sensitivity of the mental models and perceived the necessity of integrated approaches to promote progression of mental models. Implications of our findings for enhancing pre-service science teachers' topic-specific pedagogical content knowledge (PCK) associated with eclipse phenomena are also discussed here.