• Journal of Korean Elementary Science Education
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• v.43 no.1
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• pp.201-217
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• 2024

This introductory review study sought to conceptualize elementary school teachers' pedagogical content knowledge in science teaching (science PCK) by reinterpreting 11 science PCK research papers published in the Korean Journal Database from 2012 to 2023 based on the synthesized perspective of the model of teacher professional knowledge and skill (Consensus Model) proposed at the first PCK Summit in 2012 and the Revised Consensus Model (RCM) proposed at the second PCK Summit in 2016. Elementary teachers' science PCK was mainly analyzed based on Magnusson et al.'s (1999) PCK elements and described as the form of enacted PCK or personal PCK at the subject or discipline level. Personal PCK studies, which involved emotional factors, included the features of collective PCK from the RCM perspective. It was inferred that elementary school teachers' science PCK needs to be conceptualized by comprehensively considering the enacted PCK through individual teacher experiences and the collective PCK and personal PCK defined by experts.

• Journal of the Korean Society of Earth Science Education
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• v.15 no.1
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• pp.76-90
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• 2022

In this study, after applying the argument structure class design program for 20 preservice earth science teachers, we conducted individual in-depth interviews, analyzed the data, and derived a scientific argumentation PCK development model. The scientific argumentation PCK development model consists of three dimensions: Scientific argumentation PCK, PCK ecosystem, and reflective practice. Scientific argumentation PCK is demonstrated in the process of designing or executing classes using argumentation structures as an instructional reasoning tool. PCK ecosystem, consisting of the existing conventional PCK components, is a dimension surrounding the scientific argumentation PCK, and these two dimensions develop by interacting with each other. Reflective practice regulates each dimension and develops it in various ways by mediating the two dimensions of the scientific argumentation PCK and the PCK ecosystem. The conclusions drawn based on the results are as follows: First, preservice science teachers can demonstrate scientific argumentation PCK in the process of design and implementation of lessons using argumentation structures as a pedagogical reasoning tool. Second, it is necessary to develop the PCK for pedagogical reasoning tools such as scientific argumentation PCK in advance for the development of science teachers' PCK, since the scientific argumentation PCK can develop various components of the PCK ecosystem. Finally, it is necessary to use scientific argumentation PCK to support the preservice teacher's reflective practice, seeing that the scientific argumentation PCK promotes the development of PCK ecosystem components by inducing reflective practice.

• Journal of The Korean Association For Science Education
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• v.44 no.1
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• pp.105-117
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• 2024

The purpose of this study was to explore changes in elementary teachers' modeling pPCK (personal PCK) resulting from knowledge exchange within the realms of PCK described in the Refined Consensus Model (hereafter RCM). For this purpose, a professional learning community (hereafter PLC) was established for three elementary school teachers to facilitate knowledge exchange specifically focused on science modeling instructions. The study then analyzed the CoRe (content representations) written by the research participants twice to explore any changes in modeling pPCK (personal PCK). In addition, the discourse shared by the participants in the PLC and the data from the in-depth interviews were also analyzed using grounded theory research methods. The results of the study showed that there was no significant change in knowledge of the science curriculum in elementary teachers' modeling pPCK, but there were changes in orientations toward teaching science, knowledge of students' understanding in science, knowledge of instructional strategies and representations, and knowledge of assessment of science learning. Furthermore, the analysis of PLC discourse and in-depth interviews showed that modeling instructions reflection (ePCK; enacted PCK) and educational research-based modeling cPCK (collective PCK) influenced these changes in teachers' modeling pPCK. Accordingly, this study suggests recommendations for pedagogical approaches aimed at improving teachers' modeling PCK.

• Journal of Gifted/Talented Education
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• v.21 no.4
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• pp.801-828
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• 2011

In this study, we analyzed the characteristics of Pedagogical Content knowledge(PCK)'s components through actual course of teachers of science gifted students in the middle school. For this study, four middle school science teachers of gifted students belonging to the gifted education professional organizations in a metropolis were selected, each of them was physics, chemistry, biology, and earth science teacher. Two of them were full-time teachers to teach only gifted students and two were part-time teachers who had taught general students in ordinary time and specially had taught the gifted students once a week. Qualitative data were collected through classroom observations, interviews, and documents. As a result, some unique characteristics of PCK's components were identified. The teachers' orientations to teaching science were closely correlated with PCK's components. The teachers' knowledges of science curriculum were different individually. But the decisions about type of teaching(acceleration or enrichment) were connected with the objectives of gifted education and lesson objectives. Also, the teachers' knowledges of science curriculum were influenced by the knowledge of students' understanding. Teachers used different instructional strategies according to the knowledge of science curriculum and the knowledge of students' understanding. We found that PCK's components were so closely connected and could show the direction of relationships among those PCK's components. We suggested teachers' PCK model which was named "Tetrahedron Model of PCK", to explain the characteristics and relationships of PCK's components.

• Journal of The Korean Association For Science Education
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• v.40 no.5
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• pp.543-563
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• 2020

This study explores how the teaching practices of two teachers changed during scientific modeling classes. It also aims to understand these changes in terms of the teachers' modeling pedagogical content knowledge (PCK) development. The study participants were two elementary school teachers and their fifth-grade students. The teachers taught eight lessons of scientific modeling classes about the human body. The data analysis was conducted for lessons 1-2 and 7-8, which best showed the change in teaching practice. The two teachers' teaching practices were analyzed in terms of feedback frequency, feedback content, and the time allocated for each stage of model generation, evaluation, and modification. Teacher A led the evaluation and modification stages in a teacher-driven way throughout the classes. In terms of feedback, teacher A mainly used answer evaluation feedback in lesson 1-2; however, in lesson 7-8, the feedback content changed to thought-provoking feedback. Meanwhile, teacher B mostly led a teacher-driven model evaluation and modification in lesson 1-2; however, in lesson 7-8, she let her students lead the model evaluation and modification stages and helped them develop models through various feedbacks. The analysis shows that these teaching changes were related to the development of modeling PCK components. Furthermore, the two teachers' modeling PCK differed in teaching orientation, in understanding the modeling stages, and in recognizing the value of modeling, suggesting the importance of these in modeling teaching practice. This study can help improve the understanding of modeling classes by revealing the relationship between teaching practices and modeling PCK.

• Journal of The Korean Association For Science Education
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• v.41 no.2
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• pp.155-169
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• 2021

This study aims at exploring the features of science teaching orientation (STO) and its relationships with other PCK (pedagogical content knowledge) components. To do this, based on the definition of STO by Friedrichsen, Driel, & Abell(2011) and PCK model by Magnusson, Krajcik, & Borko(1999), we observed one experienced elementary teacher's science lessons for 21 lesson hours (10 hours of 'Motion of Objects' and 11 hours of 'Light and Lens') and carried out qualitative analyses of the data obtained from lessons observation, teacher interviews, and CoRe (content representation) responses. We analyzed the teacher's three aspects of STO (i.e. beliefs about the goals and purpose of science teaching, beliefs about the nature of science, and beliefs about science teaching and learning) which can converge into an overall STO of 'inquiry'. And these aspects of STO appear to interact differently with four PCK components (i.e. curriculum knowledge, learner knowledge, instructional knowledge, and assessment knowledge) depending on the topic of the lesson. It is hoped that this in-depth understanding of the features of STO and its relationship with other PCK components would provide useful information on how to monitor and improve STO and PCK of elementary teachers.

• Journal of the Korean Chemical Society
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• v.56 no.2
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• pp.274-289
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• 2012

The purposes of this study were to analyze instructional strategies of science teachers, science teachers' orientations toward science teaching by the reason which instructional strategies was used in middle school science classes, and the relations among PCK elements for suggesting a direction of improvement of PKC models. For this purpose, we selected three of middle school teachers as participants who had various teaching experience periods. Semi-structured interviews and classroom observations were gathered for data. From the data collected, we analyzed the type of instructional strategies of science teachers. On the base of these, we identified characteristics of the teachers' orientations toward teaching science. From the reason that instructional strategies was used, we could ascertain that knowledge of science curriculum and knowledge of students' learning which was component of PCK crucially affected instructional strategies of science teachers. Therefore we assured that analysis of practical instructional strategies of science teachers that showed through science instruction was the most effective method that could find out science teacher's orientation of teaching science internalized, and that knowledge of science curriculum and knowledge of students' learning was the basic component of PCK that formed instructional strategies of science teachers. On the basis of the result, a necessity for improvement of PCK models was presented.

• Journal of The Korean Association For Science Education
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• v.28 no.6
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• pp.592-602
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• 2008

The purpose of this research is to explore types of pedagogical content knowledge (PCK, hereafter) for effective science teaching. In this research, we explored three science teachers' PCK on light, who were effective in teaching the topic with particular students. The data analysis consisted of identifying the three teachers' unique PCK and ways to improve each teaching episode through the teacher meetings. These analyses, which consisted of verbal exchanges among the participants, were identified on the basis of our understanding. Using grounded theory methods, the types of science PCK drawn from this research are: (1) teaching through curriculum reconstruction, (2) teaching to help students build their own explanation models about surrounding nature, (3) teaching for learning the social language of science, (4) teaching to motivate students' learning needs based on relevance of science to students, (5) teaching through lowering students' learning demand by providing scaffolding, (6) teaching based on the teacher's understanding of students, (7) teaching through inquiry with argumentation, (8) teaching through reification of abstract science concepts, and (9) teaching none marginalized science. Common features of science teachers with quality PCK and their professionalism in teaching are discussed.

• Journal of The Korean Association For Science Education
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• v.34 no.7
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• pp.625-634
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• 2014

This study has investigated the factors that make a science teacher effective by analyzing students' perception of teacher knowledge required in enhancing their science learning. The basic components of teacher knowledge identified by previous researchers have been confirmed through Exploratory Factor Analysis (EFA). Based on the findings of the EFA, the questionnaire has been further analyzed using Confirmatory Factor Analysis (CFA) by means of Structural Equation Modeling (SEM). In addition, the differences in students' perception on the identified factors of effectiveness have also been analyzed in terms of gender and achievement level. The findings of the EFA showed that five factors of science teacher effectiveness were identified; namely, substantive knowledge, syntactic knowledge, knowledge of students' understandings, knowledge of instructional strategies, and knowledge of assessment. These five components have been divided into two categories of teacher knowledge, SMK and PCK. What we found from the CFA was the respective high correlation between substantive and syntactic knowledge, knowledge of students' understanding and instructional strategies and the low correlation between substantive knowledge and knowledge of instructional strategies. Students perceived substantive knowledge as the most effective factor, knowledge of assessment as the least effective factor. Also, there have been considerable differences in students' perception by gender and achievement level. We proposed, based on the findings, that SMK and PCK need to be integrated into a coherent manner for the effective science teaching practice. This study provides some implications for science teacher professional development and the improvement of science teacher preparation program.

• Journal of Life Science
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• v.20 no.2
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• pp.213-218
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• 2010

In the present study, we investigated anti-proliferative activities of capsaicin and gene expression changes in response to capsaicin treatment in human colorectal HCT116 cells. The results showed that capsaicin decreased cell viabilities in a dose dependent manner and induced global gene expression changes. We found that 103 genes were up-regulated more than twofold, whereas 153 genes were down-regulated more than twofold by $100\;{\mu}M$ capsaicin treatment. Among the up-regulated genes, we selected 4 genes (NAG-1, DDIT3, GADD45A and PCK2) and performed RT-PCR to confirm the microarray data. We found that $100\;{\mu}M$ of capsaicin increased tumor suppressor p53 gene expression. In addition, the results showed that NAG-1, DDIT3 and GADD45A expressions were not dependent on p53 presence, whereas PCK2 expression. The results of this study may help to increase our understandings of the molecular mechanism of anti-proliferative activity mediated by capsaicin in human colorectal cancer cells.