• Journal of The Korean Association For Science Education
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• v.26 no.6
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• pp.753-764
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• 2006

The concept of blood circulation is so complex, dynamic and abstract that students have difficulty in understanding it and students' preconceptions hardly change into scientific concepts even after the lessons. The purpose of this study is to examine middle school, high school, and undergraduate students' understanding of blood circulation and to find the reason why the lack of deep understanding is displayed in students' explanations for the blood circulation. The study consists of three parts. First, the test was designed to investigate students' ideas for blood circulation as components of the structure, the function, the behavior and the mechanism. Second, the test was applied to 7th, 10th and 13th graders to investigate the students' understanding of blood circulation and categorize the types of students' blood circulation model according to their academic level. Finally, the concepts the students had little understanding of were analyzed to decide which ontological category they fell into and further to inquire the characteristics of each concept. The results showed that many students comprehend the structure and the function of blood circulation components well, and there was no significant difference in students' understanding according to the academic level. In contrast, understanding the behavior and the mechanism of circulatory components has remarkably improved in high school students and undergraduates majoring in science and engineering. Also, students' blood circulation models were classified into seven different types. High school students and undergraduates majoring in science and engineering demonstrated a significantly higher percentage on the type of double-loop-branch compared to other academic levels. In addition, it was found that the lack of deep understanding was caused by students' misconceiving the 'equilibrium' category as 'event' category.

• School Mathematics
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• v.12 no.4
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• pp.547-561
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• 2010

Even though statistics is considered as one of the areas of mathematical science in the school curriculum, it has been well documented that statistics has distinct features compared to mathematics. However, there is little empirical educational research showing distinct features of statistics, especially research into the understanding of statistical concepts which are different from other areas in school mathematics. In addition, there is little discussion of a relationship between the ability of mathematical thinking and the ability of understanding statistical concepts. This study extracted some important concepts which consist of the fundamental statistical reasoning and investigated how mathematically high achieving students understood these concepts. As a result, there were both kinds of concepts that mathematically high achieving students developed well or not. There is a weak correlation between mathematical ability and the level of understanding statistical concepts.

• Communications of Mathematical Education
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• v.13 no.2
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• pp.655-691
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• 2002

16개의 무한개념 문제를 가지고 47명의 대학생에게 개별 검사하여 무한개념의 이해 과정을 설명하고자 시도했다. 전문가-초심자의 조망에서 미시발생적 방법을 사용하여 2명의 사례를 비교 ${\cdot}$ 분석하였다. Cifarelli(1988)'의 반성적 추상과 Robert(1982)와 Sierpinska(1985)의 무한개념의 3단계를 설명의 틀로 사용하였다. 실무한 개념 수준으로 이행한 사례 P는 그렇게 하지 못한 L보다 높은 수준의 반성적 추상을 보여 주었다. 따라서 반성적 추상은 무한개념의 이해에 결정적인 사고의 메카니즘으로 볼 수 있다.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.2
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• pp.283-309
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• 2016

The purpose of this study is to investigate gifted students in elementary mathematics how they understand of situations involving multiplication and concepts of multiplication. For this purpose, first, this study analyzed the teacher's guidebooks about introducing the concept of multiplication in elementary school. Second, we analyzed multiplication problems that gifted students posed. Third, we interviewed gifted students to research how they understand the concepts of multiplication. The result of this study can be summarized as follows: First, the concept of multiplication was introduced by repeated addition and times idea in elementary school. Since the 2007 revised curriculum, it was introduced based on times idea. Second, gifted students mainly posed situations of repeated addition. Also many gifted students understand the multiplication as only repeated addition and have poor understanding about times idea and pairs set.

• Communications of Mathematical Education
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• v.27 no.4
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• pp.499-521
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• 2013

This paper analyzed the relationship between middle school students' belief about understanding with regard to mathematical concepts, procedures, and applications of the procedures. In order to gain our purpose, the academic achievement results of midterm examination of 139 middle school students and the surveys about their beliefs about understanding, mathematical concepts, and mathematical procedures were collected. And the cross analysis and the frequency analysis of SPSS were conducted. The research results showed that students' belief about understanding are irrelevant to their academic achievements. And the percentage of the students who believe that they understand was almost the same with the percentage of the students who understand the procedures. But there were differences between the percentage of the students who believe that they understand and the percentage of the students who understand the concepts. Through these, it is conformed. Students' belief about understanding does not mean they understand mathematical concepts. They just can solve mathematical problems through mechanical procedures.

• Journal of the Korean Chemical Society
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• v.48 no.4
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• pp.399-413
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• 2004

In this study, a survey was conducted of students of elementary through college on their conceptions of phenomenon related with dissolution, saturation, and extraction. The teaching strategies of elementary and secondary teachers related to dissolution phenomena were also investigated. Most of elementary and secondary school students thought of dissolution as a phenomenon in which particles broke into the spaces between other particles. This explanation called 'space conception' can be sought in elementary school science textbooks. Some of high school students also had this type of thought. A concept of dissolution phenomenon as 'hydration through attraction of solvent and solute' was held by most of students of 11th, 12th grade, and college. This explanation called 'attraction concept' can be sought in high school chemistry textbooks for 11th and 12th grade. But many students of elementary through college used analogies and models related to 'space conception' when they tried to explain the dissolution phenomena. This indicates that the 'attraction concept' was not firmly established in the students' cognition. 90% of elementary school teachers thought and taught dissolution as a phenomenon in which two different size particles were mixing together like as mixing beans and millets. The model does not represent the attractions among solvent-solvent particles, solvent-solute particles, and solute-solute particles. This model only represents the space size effect (smaller size particles fitting into the spaces of larger size particles). Half of the secondary school teachers also had 'space conception' and only 20% of the teachers had 'attraction concept' Many teachers who had 'attraction concept' used to represent explanation related to 'space conception' for teaching dissolution.

• Journal of the Korean Chemical Society
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• v.61 no.1
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• pp.34-44
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• 2017

The purpose of this study was to analyze the conception type change and to investigate the effect of understanding on concepts in electrochemistry after general chemistry lessons. The significant differences in concept understanding of electrochemistry were shown in both groups. Statistically significant gains in both groups were as shown in distinguishing the chemical cell, in identifying the anode and cathode, and in understanding current formation and flow, while, significant achievements in understanding the role of the salt bridge, and the need for a standard half-cell were not found. Taking elective chemistry II in high school had an effect on understanding related concepts of electrochemistry in general chemistry lessons. It was shown that many freshmen had difficulties in understanding exact related concepts in several kinds after general chemistry lessons. In order to solve these problems, it is necessary to teach contents of the basic concepts in electrochemistry exactly and to hold supplementary lessons.

• Communications of Mathematical Education
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• v.15
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• pp.175-180
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• 2003

본 연구에서는 중학교 과정에서 기본이 되는 개념이라 할 수 있는 음수 개념의 이해실태를 중학교 1학년 학생들을 대상으로 분석하고, 예비수학교사들이 음수 개념에 대해 어느 정도의 '교수학적 내용지식'을 갖고있는지 파악하여 분석하고자 하였다. 또 학생들이 겪는 음수개념 학습에서의 어려움을 해결하기 위한 방안을 제시하여 음수 개념 지도에 도움을 주고자 한다.

• Communications of Mathematical Education
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• v.22 no.3
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• pp.311-335
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• 2008

The importance of students' precise understanding of mathematical definitions, formulas, and theorems can not be underestimated. In this survey research, we attempted to evaluate students' understanding of the concepts of five topics -limit, continuity and intermediate theorem, derivative, application of derivative and integral. On the basis of the research result, this paper suggests that we need to 1) be more inventive and speculative in making test problems, 2) explain the examples and counter-examples more concretely, 3) stress and repeat the basic concepts on the stage of introducing new concepts, 4) develop more effective problems for the measure of students' understanding of mathematical concepts, 5) use developed problems in actual teaching.

• Journal of The Korean Association For Science Education
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• v.18 no.4
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• pp.463-472
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• 1998

Biotechnology is the process of using biological system for the production of materials. Genetic engineering, a subset of biotechnology, is the process of altering biological systems by the purposeful manipulation of DNA It is a new field in biology and no topic in biology is more likely to impact our personal lives and is therefore more worthy of our attention and understanding. The purpose of this study was to investigate students' understanding of the concepts of biotechnology, and a test tool which is made up of 20 basic questions was developed for the study. The subject of this study was high school students and the sample size was 486. In order to find out the source of students' misunderstanding, we also analysed high school textbooks and teachers were given the same tool applied to students. Two-way ANOVA was used for the analysis. Major findings of this study are as following; 1. Mean score of students was 41, and there was a significant difference between the scores of boys and girls(p<0.05). Female students scored higher than male students. The variables "region" and "major" had no significant influence. 2. Students' the most misunderstood concepts were "monoclonal antibody" and "gene cloning". Many students thought that a plamid DNA originally has a useful DNA in it, which is apparently wrong. 3. Mean score of teachers was 82, and the variabes of gender and career did not have statistically significant influence on the result(p>0.05). 4. Teachers got the lowest scores on the concepts of "gene therapy", "the accomplishment of biotechnology in agriculture and medicine", and "plasmid DNA". The results of item analysis implied that teachers' misunderstanding might be a part of the sources of students' misunderstaning. 5. Out of 18 basic concepts selected in the study, only 10 concepts were explained well enough in most textbooks. The results of item analysis indicated that textbooks also could be a part of the source of students' misunderstanding.