• 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.

• Journal of The Korean Association For Science Education
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• v.31 no.1
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• pp.99-114
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• 2011

Developing pedagogical content knowledge (PCK) has been emphasized as one of the requirements for science teacher's professionalism, and it should be done from systematic teacher training courses. In this study, we investigated the components considered in planning instruction and the difficulties encountered in implementing it in PCK held by secondary pre-service teachers. Twenty-seven juniors at a college of education in Seoul were asked to perform teaching demonstrations using scientific instruction models. They were also requested to write reflective journals and interview. Analyses of the results revealed that teaching strategies and learners' cognitive affective aspects were considered by most secondary pre-service teachers, whereas curriculum and assessment were regarded by few of them. For examples, choosing instruction models and organizing instructions were concerned in teaching strategies. They also considered learners' cognitive affective aspects for selecting experiments as main activities. Only few considered learners' prior-knowledge. Most difficulties encountered in planning instruction and implementing it appeared in teaching strategies. Educational implications of these findings are discussed.

• Journal of The Korean Association For Science Education
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• v.33 no.5
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• pp.1021-1040
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• 2013

In order to explore the influences of coteaching through mentoring upon the teaching professionalism of beginning science-gifted education teachers, this case study deeply investigated the change processes in the aspects of pedagogical content knowledge (PCK). Two beginning teachers planned, performed and reflected together their science instructions for science-gifted students in secondary school during four 3-hour classes. Since the second instruction, pre-, during-, and post-mentoring were conducted, we collected various data related to teachers' planning processes, videotaped all coteaching science classes, and wrote field notes. We also recorded in-depth interviews with the teachers and the whole process of mentoring. All the data were analyzed by using the constant comparative method. The results of the analyses indicated that coteaching through mentoring positively changed the teachers' PCK. Above all, we found that coteaching and mentoring strategies generated a significant synergy effect through a mutually complementary relationship. The teachers developed deep practical knowledge about the enrichment curriculum, which placed more emphasis on developing cognitive and/or affective characteristics of science-gifted students. The teachers also improved their knowledge about the characteristics of science-gifted students and the instructional strategies appropriate for developing them. Moreover, practical knowledge about assessment domains and methods used in science-gifted education were improved. Knowledge on science content necessary for effective inquiry instruction was also improved.

• Journal of The Korean Association For Science Education
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• v.33 no.6
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• pp.1219-1236
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• 2013

The purpose of this study was to investigate the association between subject matter knowledge (SMK) and pedagogical content knowledge (PCK) for science teachers. To this end, a total of 26 secondary Earth science teachers participated in this study and a concept diagnostic questionnaire and a lesson planning task of atmospheric pressure were devised to give an indication of participating teachers' SMK and PCK, respectively. The results of this study are summarized as follows: First, participating teachers showed a variety of SMK levels about atmospheric pressure. Second, teachers at high level of SMK focused on 'supplementary' and 'fundamental' curriculum contents for in-depth conceptual understanding, but teachers at low level of SMK, on the contrary, stressed 'applicative' curriculum contents. Third, teachers at high level of SMK grasped students' misconceptions and difficulties in learning atmospheric pressure far more concretely than teachers at low level of SMK. Lastly, teachers at high level of SMK showed a tendency to use learner-centered instructional strategy by utilizing students' prior knowledge, but teachers at low level of SMK were inclined toward teacher-directed concept explanation. Based on this study, some implications for effective science teacher preparation programs were also discussed.

• Journal of the Korean Chemical Society
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• v.66 no.2
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• pp.150-162
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• 2022

In this study, we investigated pre-service science teachers' NOS-PCK by analyzing their NOS lesson planning and demonstration. Four pre-service science teachers participated in the study. They planned and demonstrated NOS lessons in the context of 'Science Inquiry Experiment' developed under the 2015 Revised National Curriculum. Their lessons were observed. All of the teaching-learning materials were collected, and semi-structured interviews were also conducted. The analyses of the result revealed that pre-service teachers mainly referred to the curriculum and textbooks when selecting the NOS learning objectives. However, they felt difficulty because the curriculum and textbooks did not clearly present the NOS to be dealt. Although all of them took explicit approaches, there were not many open and divergent reflective approaches. In addition, they expected that high school students would consider scientific knowledge absolute and would have negative perceptions of NOS lessons. They rarely assessed students' NOS learning, and were reluctant to assess. Finally, most of them had a negative perception that learning NOS is not necessary for all students. On the bases of the results, educational implications for improving the expertise of pre-service science teachers in NOS lessons were discussed.

• Journal of Korean Elementary Science Education
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• v.41 no.4
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• pp.690-700
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• 2022

This study aimed to compare academic passion for science pedagogical content knowledge (PCK) between pre-service and in-service elementary teachers. In addition, a comparison between passion for science subject matter knowledge and passion for science pedagogical knowledge was made for each group of teachers. Participants comprised 182 students from colleges of education and 161 in-service teachers. We analyzed between- and within-subject comparisons for each component of academic passion for science PCK. The results of this study are as follows: First, between-subject comparison demonstrated that, in academic passion for science subject matter knowledge, in-service teachers had a higher passion for "liking" and "importance" than pre-service teachers, whereas pre-service teachers had a higher passion for "time/energy investment" than in-service teachers. In academic passion for science pedagogical knowledge, pre-service teachers had a higher passion for "time/energy investment" than in-service teachers. Second, the within-subject comparison showed that only "harmonious passion" was higher for science pedagogical knowledge than science subject matter knowledge in pre-service teachers. However, "liking", "importance", "time/energy investment", and "obsessive passion" were higher for science subject matter knowledge than science pedagogical knowledge in in-service teachers. The educational implications are discussed.

• Journal of The Korean Association For Science Education
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• v.42 no.2
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• pp.265-275
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• 2022

In this study, focusing on science education in the future society, we explored students' key competencies to be cultivated for the future society, and the role and PCK expertise necessary for science teachers, who are the main agents of competency-based education to nurture these key competencies. A survey conducted among earth science teachers across the country results in 105 valid responses being obtained. The research results are discussed in terms of students' key competencies to be nurtured for the future society, the role and the expertise of science teachers required for competency-based education, and the structural relationship between the teacher role and teacher expertise. We also conducted network analysis to examine the relationship between student competency and teacher expertise, and the structure between the teacher's role and expertise. Main results include that communication and collaboration skills are the most important for students in the future society as core competencies. For science teachers, providing opportunities for collaboration-oriented activities are deemed as the most important. Regarding the structural relationship between the teacher's role and the teacher's expertise, there is a clear relationship with roles such as providing opportunities for collaboration-oriented activities and utilizing various materials and contents in relation to the expertise related to the science teaching practice. Based on the results, ways to promote student's agency based on raising teachers' awareness of the student's competencies, the inter-relatedness of the teacher's role and the teacher's expertise, and the totality of teachers' expertise were suggested.

• Journal of Korean Elementary Science Education
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• v.42 no.1
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• pp.1-16
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• 2023

This study investigated the level of academic passion for pre-service elementary teachers' science pedagogical content knowledge (PCK) and the factors that influence the passion. To this end, 182 first to fourth grade students in advanced non-science majors who were taking science-related courses in the second semester were selected, and two tests were then administered to evaluate their academic passions for science subject matter knowledge and science pedagogical knowledge. Individual in-depth interviews were also conducted with some of the participants. It was found that the factors such as "importance" and "harmonious passion" for learning science subject matter knowledge and science pedagogical knowledge were found at a high level. On the other hand, the factors such as "like" and "investment of time and energy" were slightly higher than normal, and the factor such as "obsessive passion" was slightly lower than normal. The differences in academic passion for science subject matter knowledge and science pedagogical knowledge were greater according to the high school track than the grade. The pre-service elementary teachers selected more often the factors such as "individual interests", "high school track", "contents of science-related courses at the university of education", "characteristics of professor in charge of science-related courses at the university of education", and "experience in teaching practicum" as the factors that influenced their academic passion for science subject matter knowledge and science pedagogical knowledge. However, there was a slight difference in the selection ratio depending on the high school track.

• Journal of The Korean Association For Science Education
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• v.43 no.6
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• pp.521-531
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• 2023

In this study, we analyzed contextualized NOS lessons planned by preservice teachers from the perspectives of PCK. Eight preservice teachers who had completed all of the curriculum at the College of Education located in Seoul participated in the study. CoRe and teaching and learning guidance were collected. Interviews were also conducted. We used analytical induction to analyze the collected data. The analyses of the results revealed that the NOS learning goals selected by the preservice teachers were different depending on the context of the NOS lessons. In addition, the preservice teachers were unable to sufficiently explain the value of learning NOS. All of the preservice teachers were worried that their students would not understand NOS properly, and they faced various difficulties in dealing with NOS and science content. They thought that if their students conducted experiments, errors could cause problems for students learning NOS. Meanwhile, they guessed their students' preconceptions and misconceptions of NOS based on their experience. The preservice teachers also thought that their students' concept of science and cognitive development stage would affect their NOS learning. Although the preservice teachers used various strategies to teach NOS, NOS was often not explicitly addressed. Also, they were reluctant to evaluate NOS in lessons. Based on the above results, educational implications for preservice teacher education were proposed.