• Journal of The Korean Association For Science Education
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• v.26 no.1
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• pp.9-15
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• 2006

Students have often experienced difficulties in understanding the concept of the particulate nature of matter despite its importance in chemistry. Although various instructional methods have been suggested for teaching this concept, systematic studies have been rarely conducted. Therefore, this study investigated the effects of drawing and analyzing pictures. Three classes of 7th graders at a coed middle school in Seoul were assigned to the control group, the drawing group, and the analyzing group, respectively. Students were taught about the three states of matter and the motion of molecules for 8 class periods. The instructional effects on student conception, achievement, and science learning motivation were investigated by student visual learning styles. Results revealed that the scores of a conceptions test and a science learning motivation test for both the drawing group and the analyzing group were higher than those for the control group. Additionally, the scores of the science learning motivation test were also found to be higher for students with a more visual learning style than their counterparts.

• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.150-157
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• 2010

In this study, we investigated the differences of mapping understanding and the types of mapping errors by the levels of students' cognitive/affective variables and the relationships between mapping understanding and these variables in learning 'concentration and reaction rate' with analogy. After administering the tests regarding logical thinking ability, visual imagery ability, analogical reasoning ability, self efficacy, and need for cognition as pretests, students learned with analogy. Then, students' familiarity and mapping understanding were examined. Analyses of the results revealed that the scores of the mapping understanding for the students with higher levels of all cognitive/affective variables except visual imagery ability and familiarity were significantly higher than those for the students with lower levels. The differences in the types of the mapping errors such as overmapping, failure to map, impossible mapping, artificial mapping, mismapping, rash mapping, and retention of a base feature were also found by the levels of students' cognitive and affective variables. The scores of students' mapping understanding were positively correlated with those of all cognitive and affective variables. The results of multiple regression analysis indicated that students' science achievement, logical thinking ability, and familiarity were significant predictors of mapping understanding. Educational implications of these findings are discussed.

• Journal of the Korean Chemical Society
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• v.57 no.1
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• pp.115-126
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• 2013

In this study, we developed a explicit and reflective scientific inquiry learning program about nature of scientific inquiry, and compared its instructional influences with those of implicit scientific inquiry learning. We also compared students' perceptions of the program. Eighth graders at a middle school were assigned to the treatment and the control groups. The students of the treatment group participated in the program, while those of the control group participated in general scientific inquiry instruction. The analyses of the results revealed that the program was more effective in improving students' epistemological views on scientific inquiry than general scientific inquiry learning. However, there were no statistically significant differences in both test scores of science achievement and enjoyment of science lessons. The students of the treatment group perceived that group discussion on the nature of scientific inquiry was an advantage of the program. However, they still had difficulties in performing group discussion, understanding the nature of scientific inquiry, and writing and presenting their thoughts. Educational implications of these findings are discussed.

• Journal of the Korean Chemical Society
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• v.65 no.3
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• pp.197-202
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• 2021

In this study, activated clay treated with H₂SO₄ (20% by weight) and heat at 90 ℃ for 8 h for acid white soil was used as an adsorbent for the removal of PO₄^3--P in water. Prior to the adsorption experiment, the characteristics of activated clay was examined by X-ray Fluorescence Spectrometry (XRF) and BET surface area analyser. The adsorption of PO₄^3--P on activated clay was steeply increased within 0.25 h and reached equilibrium at 4 h. At 5 mg/L of low PO₄^3--P concentration, roughly 98% of adsorption efficiency was accomplished by activated clay. The adsorption data of PO₄^3--P were introduced to the adsorption isotherm and kinetic models. It was seen that both Freundlich and Langmuir isotherms were applied well to describe the adsorption behavior of PO₄^3--P on activated clay. For adsorption PO₄^3--P on activated clay, the Freundlich and Langmuir isotherm coefficients, K_F and Q, were found to be 8.3 and 20.0 mg/g, respectively. The pseudo-second-order kinetics model was more suitable for adsorption of PO₄^3--P in water/activated clay system owing to the higher correlation coefficient R² and the more proximity value of the experimental value q_e,exp and the calculated value q_e,cal than the pseudo-first-order kinetics model. The results of study indicate that activated clay could be used as an efficient adsorbent for the removal of PO₄³-P from water.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.1
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• pp.2-15
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• 1982

In this report, a total domestic demand for major commercial fertilizer for crop production in Korea up to 1996 was estimated. The agricultural products and area for demand for both 1982 and 1986 was quoted from the estimate of the 5th Five-year Economic plan. And the demands estimated for 1991 and 1996 reflected possible changes of diet from cereal to meat and their indirect effects on the increase of cereal consumption. As the advanced countries followed, consequently, the demands for soybean, corn and other feed grains were expected to be increased as well as the land for growing those crops. 1. Total annual demands for nitrogen, phosphorus and potassium fertilizers were estimated 1,050,000M/T, 1,110,000M/T, 1,280,000M/T and 1,010,000M/T for the year 1982, 1986, 1991, and 1996 respectively. 2. It was assumed that there would be difficulties in self-sufficiency of grains at the cost of the maximum utilization of land and fertilizers in 1996. 3. It was clear that the increase of the productivity per unit area is possible by improving the conditions of arable land which could resulted a self-sufficiency of food in Korea. As a consequence, the demand for fertilizers at that time would exceed the level of estimates. 4. The recent decrease in demand for commercial fertilizers (currently estimated 850,000M/T) was due to an inadequate application of fertilizers for respective crop reqirement. This inadequacy should be checked and encouraged the consumptions of fertilizers to be increased by supporting the price of grain.

• Journal of the Korean earth science society
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• v.28 no.4
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• pp.453-461
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• 2007

This study analyzed all of the research articles published in six of the Korean science education journals in the past three decades. The purpose of this research synthesis was to identify gender differences in hundreds of research articles accomplished at the personal, local, and national level that have repeatedly been reported in several international comparative studies. There were few of articles that focused on gender issues, but 279 articles presented a result of gender issues separately. Of the 279 articles, we finally analyzed 225 research articles for a statistical significance. The articles were divided into two types of research method: test-based studies and experiment-based studies. The results of research synthesis in test-based studies were as follows: The largest number of studies reported male superiority in science knowledge and science-related attitude, which is similar to the results of recent international studies. In particular, gender differences were the biggest in science-related attitudes and the least in scientific process skills. The result of research synthesis in experimental studies was that the largest number of articles did not show significant gender differences in the effect of the applied program. It is noteworthy that the applied science education programs tend to be more effective in improving female students' scientific attitude and male students' science knowledge. It is necessary to develop more gender-inclusive science programs for female students to feel science more positively.

• Journal of Korean Home Economics Education Association
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• v.5 no.1
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• pp.97-111
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• 1993

본 연구는 국민학교 실과 과목의 식품 영양 단원에 관한 교사, 학생의 인지 및 학생의 지식, 태도, 기능 평가를 위하여 71개 인천시내 공립 국민학교 4,5,6학년 교사 510명과 12개교학생 1,754명을 대상으로 설문조사를 통한 내용을 분석한 것으로 연구의 목적은 1)실과의 정해진 교육목표에 관한 교사의 인지정도 규명 2)식품, 영양 단원에서 교사가 중요하다고 인지하는 내용과 가르치기에 어려움을 느끼는 내용 규명 3)교사가 인지하는 식품영양 단원학습을 증진하기 위한 요소 4) 학생들이 흥미를 느끼는 내용 5)본 단원 학습 후 학생의 지식, 태도, 기능 정도 6)지식, 태도 기능간의 상호 상관관계 규명 등이며 그 연구결과는 다음과 같다. 1. 교사들이 인지하는 실과의 정해진 교육목표는 거의 모두가 중요한 것으로 나타났다. 2. 교사들이 인지하는 식품 영양 단원의 중요한 내용은 영양과 질병과의 관계, 식품위생, 식품저장 등이며, 가장 중요하지 않은 내용으로는 영양 필요량이었다. 또한, 지도에 어려움을 느끼는 내용은 영양 필요량, 조리준비, 식품구성/함유량 등이며 어려움을 느끼지 않는 내용은 영양과 질병과의 관계, 식품위생, 식품저장 등이었다. 3. 교사가 인지하는 단원 학습 증진을 위한 긍정적 요소는 적합한 실습설비와 자료, 시청가자료등이었고 부정적 요소는 남교사, 실험 실습이 필요한 부분은 숙제로 미루는 것 등이었다. 4. 학생들이 흥미를 느끼는 내용으로는 간단한 음식 만들기, 영양소의 기능, 영양문제 등이었고, 쥬스나 차 준비, 조리연료, 부엌용구 사용법 등은 흥미를 느끼지 못하는 내용이었다. 5. 학생의 학업성취 중 지식은 4학년이 식품위생, 기초식품군이, 5학년은 알맞은 조리용구, 조리원리, 6학년은 여가활용의 뜻, 올바른 예절 등이 90% 이상 바르게 답하였고 5학년의 삶은 달걀의 화학적 변화, 감자의 주된 영양 등은 60%이하였다. 6 태도 테스트 결과는 5학년이 4,6학년보다 약간 높은정도(Mn=3.653) 였으나 기능테스트에서는 4학년이 5,6학년보다 약간 낮게 (Mn=3.0) 나타났다(구체적인 것은 본문 참조). 7, 4, 5, 6학년 모두 지식, 태도 기능 간에 정적 상관을 나타내었는데 특히 태도와 기능 사이에는 4학년 r=.7166, 5학년 r=.5175, 6학년 r=.6796을 나타내었고 지시과 태도(4학년 r=.1546, 5학년 r=.0872, 6학년 r=.2192)와 지식과 기능사이에서는 (4학년 r=.1631, 5학년 r=.0585, 6학년 r=.2521)태도와 기능간보다 약한 상관관계를 보였다.

• Journal of The Korean Association For Science Education
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• v.27 no.5
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• pp.394-403
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• 2007

In this study, the effects of reciprocal peer questioning (RPQ) strategy upon students' concept learning were investigated. Ninety-two seventh graders at a co-ed middle school were assigned to control, reciprocal peer tutoring (RPT), and RPQ groups. The students were taught about 'three states of matter' and 'motion of molecules' for 12 class hours. Regardless of students' prior science achievement level, the RPQ group showed the highest scores among the three groups in the test of conceptual understanding, and the RPT group performed better than the control group. For high-level students, the scores of the RPQ group were significantly higher than those of the other groups in the test of the concept application, and those of the RPT group were higher than those of the control group. For low-level students, the scores of the RPT and RPQ groups in the concept application test were significantly higher than those of the control group, while those of the RPT and RPQ groups were not significantly different. These results indicated that verbal interaction by reciprocal tutoring helped students to understand chemical concept learning, and that using self-generated questions was more effective. Therefore, RPQ strategy is suggested to become one of the useful instructional methods to facilitate verbal interaction and concept learning in middle school science instructions.

• Journal of the Korean Chemical Society
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• v.58 no.5
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• pp.463-477
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• 2014

The purpose of this study is to investigate the teaching-learning effects in the experimental classes for the 'Redox' unit of science textbook of 11th grade using self-regulated learning strategy. Simultaneously, the effects of teaching-learning through the student's characteristics of the scientific high school were also included. The experimental and the controlled groups were selected by the teaching-learning method established on self-regulated learning strategy and regular laboratory activity based on the teacher' instruction, respectively. The questionaries of the scientific inquiry and scientific attitude were examined by the student. For their achievement, the total score which was obtained from the formative evaluation and performance assessment was utilized. After the laboratory activity for the unit grounded on the self-regulated learning strategy, the mean values of the scientific inquiry, scientific attitude, and achievement by the experimental group were higher than those of the controlled group. There was significant difference between the two groups in the post-test. By the results of the post-test for the experimental group, there has been somewhat relationship between the self-regulated learning strategy and the scientific inquiry, the scientific attitude, and the scientific achievement.

• Journal of the Korean Chemical Society
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• v.50 no.6
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• pp.494-505
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• 2006

This study was performed for 7th grade students to analyze by leader style, the verbal interactions between students in a small group in an MBL(Microcomputer-Based Laboratory) experiment class. The study was performed after arranging the students into four kinds of groups, including groups with leaders of inclusive, persuasive, and alienating styles and a group with no clear leader. The analysis of total frequencies of verbal interaction revealed that the group with an inclusive leader showed the highest frequency of verbal interaction, followed by the group with a persuasive leader, an alienating leader and lastly, the group with no clear leader. The group with an inclusive leader showed the highest frequency of interaction from a cognitive aspect related to question(Q), response(R), making suggestion(MS), and receiving opinions(RO), while interactions from an affective aspect related to behavioral participation(BP) and students' attitudes(SA) were observed more often in a group including an alienating leader than in any other group. An analysis of characteristics of verbal interaction according to leader style showed that a group with an inclusive leader had a permissive atmosphere. It also showed that all members of the group actively participated in discussion and they had a sense of belonging and self-pride with their group. In a group with a persuasive leader, the leader took the lead of most experimental and discussion activities and he was rarely challenged by other students in the group. Rather, other group members showed a tendency to depend on their leader. In a group with an alienating leader, the relationship between leader and members of the group was not harmonious and unfiltered expressions of dissatisfaction and ignorance often took place. The leader's lack of concern about members' low achievement became an obstacle in active discussion. In a group with no clear leader, most interactions during discussion were short and simple. Many answers to the question given by their members were not clear and the interactions were sometimes interrupted for a short while.