• 대한수학교육학회지:학교수학
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• 제4권1호
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• pp.1-13
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• 2002

The purpose of this study is to investigate the reasons and backgrounds of drawing auxiliary lines in the proof of geometry. In most of proofs in geometry, drawing auxiliary lines provide important clues, thus they play a key role in deductive proof. However, many student tend to have difficulties of drawing auxiliary lines because there seems to be no general rule to produce auxiliary lines. To alleviate such difficulties, informal activities need to be encouraged prior to draw auxiliary lines in rigorous deductive proof. Informal activities are considered to be contrasting to deductive proof, but at the same time they are connected to deductive proof because each in formal activity can be mathematically represented. For example, the informal activities such as fliping and superimposing can be mathematically translated into bisecting line and congruence. To elaborate this idea, some examples from the middle school mathematics were chosen to corroborate the relation between informal activities and deductive proof. This attempt could be a stepping stone to the discussion of how to teach auxiliary lines and deductive reasoning.

• 한국수학교육학회지시리즈A:수학교육
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• 제37권1호
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• pp.73-85
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• 1998

The purpose of this study is to investigate the understanding of middle school students on the meaning of proof and to suggest a teaching method to improve their understanding based on three levels identified by Kunimune as follows: Level I to think that experimental method is enough for justifying proof, Level II to think that deductive method is necessary for justifying proof, Level III to understand the meaning of deductive system. The conclusions of this study are as follows: First, only 13% of 8th graders and 22% of 9th graders are on level II. Second, although about 50% students understand the meaning of hypothesis, conclusion, and proof, they can't understand the necessity of deductive proof. This conclusion implies that the necessity of deductive proof needs to be taught to the middle school students. One of the teaching methods on the necessity of proof is to compare the nature of experimental method and deductive proof method by providing their weak and strong points respectively.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제24권2호
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• pp.325-344
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• 2010

본 연구는 중학생을 대상으로 학생들이 경험적 증명과 연역적 증명에 대한 선호를 결정할 때 영향을 미치는 요인을 분석하였다. 47명의 중학생에게 설문지를 통하여 자료를 수집하고 응답들을 분석한 결과, 경험적 증명과 연역적 증명의 선호에 영향을 미치는 요인들로 측정, 수학적 원리, 다양한 예를 통한 검증과정에 대한 인식들이 공통적으로 나타났다. 이 요소들은 경험적 증명과 연역적 증명의 선호와 비선호를 결정짓는 요인으로써, 선호하는 증명에 따라 상호 배타적으로 나타나지 않고 증명 선호에 영향을 미쳤다. 이를 통해 본 연구에서는 학생들이 특정 증명을 선호할 때, 한 증명에 대한 비선호와 다른 증명에 대한 선호가 동시에 작용할 수 있다는 결론과 함께 한 증명에 대한 선호요인을 보는 것만으로는 학생들의 증명 선호 이유를 정확히 파악할 수 없을 것이라는 가능성을 제언한다.

• 대한수학교육학회지:수학교육학연구
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• 제9권2호
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• pp.419-438
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• 1999

This paper explored the impact of dynamic geometry software such as CabriII, GSP on student's understanding deductive justification, on the assumption that proof in school mathematics should be used in the broader, psychological sense of justification rather than in the narrow sense of deductive, formal proof. The following results have been drawn: Dynamic geometry provided positive impact on interacting between empirical justification and deductive justification, especially on understanding the necessity of deductive justification. And teacher in the computer environment played crucial role in reducing on difficulties in connecting empirical justification to deductive justification. At the beginning of the research, however, it was not the case. However, once students got intocul-de-sac in empirical justification and understood the need of deductive justification, they tried to justify deductively. Compared with current paper-and-pencil environment that many students fail to learn the basic knowledge on proof, dynamic geometry software will give more positive ffect for learning. Dynamic geometry software may promote interaction between empirical justification and edeductive justification and give a feedback to students about results of their own actions. At present, there is some very helpful computer software. However the presence of good dynamic geometry software can not be the solution in itself. Since learning on proof is a function of various factors such as curriculum organization, evaluation method, the role of teacher and student. Most of all, the meaning of proof need to be reconceptualized in the future research.

• 대한수학교육학회지:수학교육학연구
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• 제9권1호
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• pp.245-261
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• 1999

Proof is an essential characteristic of mathematics and as such should be a key component in mathematics education. But, teaching proof in school mathematics have been unsuccessful for many students. The traditional approach to proofs stresses formal logic and rigorous proof. Thus, most students have difficulties of the concept of proof and students' experiences with proof do not seem meaningful to them. However, different views of proof were asserted in the reassessment of the foundations of mathematics and the nature of mathematical truth. These different views of justification need to be reflected in demonstrative geometry classes. The purpose of this study is to characterize the types of students' justification in demonstrative geometry classes taught using dynamic software. The types of justification can be organized into three categories : empirical justification, deductive justification, and authoritarian justification. Empirical justification are based on evidence from examples, whereas deductive justification are based logical reasoning. If we assume that a strong understanding of demonstrative geometry is shown when empirical justification and deductive justification coexist and benefit from each other, then students' justification should not only some empirical basis but also use chains of deductive reasoning. Thus, interaction between empirical and deductive justification is important. Dynamic geometry software can be used to design the approach to justification that can be successful in moving students toward meaningful justification of ideas. Interactive geometry software can connect visual and empirical justification to higher levels of geometric justification with logical arguments in formal proof.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제13권3호
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• pp.217-233
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• 2009

The purpose of this study is to describe how dynamic geometry systems can be useful in proof activity; teaching sequences based on the use of dynamic geometry systems and to analyze the possible roles of dynamic geometry systems in both teaching and learning of proof. And also dynamic geometry environments can generate powerful interplay between empirical explorations and formal proofs. The point of this study was to show that how using dynamic geometry software can provide an opportunity to link between empirical and deductive reasoning, and how such software can be utilized to gain insight into a deductive argument.

• 대한수학교육학회지:수학교육학연구
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• 제14권1호
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• pp.111-127
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• 2004

본 연구는 기하 부분의 내용이 초등학교에서 중학교로 발전 전개되는 과정에서 일부 용어의 정의와 평행선과 각의 취급에 대하여 알아보았고, 교육과정에 제시된 관련내용을 분석하고 그에 따른 현행 교과서를 살펴보았다. 다음에 관련된 분야의 일부 외국교과서를 비교 분석하여 그 상황을 알아보았다 그 결과 현행 교과서 보다 바람직한 내용의 취급을 위해서는 우선 체계적인 학습을 할 수 있도록 교육과정에 보다 적합한 학습내용과 그 취급 방법을 제시해야만 하고, 그에 따라 교과서도 보다 적합하게 집필되어야 함을 제시하였다. 이를테면 용어의 정의는 반복하여 충분히 이해하도록 하고, 특히 교육의 다양성을 위해서 평행선의 성질에 관한 내용은 공준으로 도입하여 활용할 수도 있고, 우수한 학생들은 증명을 하여 활용할 수도 있도록 다양한 취급을 하는 것이 바람직함을 제시하였다. 그리고 특히 현행 교과서에서는 <7-나 단계에서 취급되고 있는 맞꼭지각의 성질과 평행선의 성질과 같은 연역적 추론에 의해서 증명될 수 있는 내용들은 18- 나 단계>로 이동을 하여 학습하는 것이 학습 체계의 연계에 바람직함을 제시하였다.

• 대한수학교육학회지:수학교육학연구
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• 제11권2호
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• pp.385-402
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• 2001

The purpose of this study is to conceptualize 'proof' school mathematics. We based on the assumption the following. (a) There are several different roles of 'proof' : verification, explanation, systematization, discovery, communication (b) Accepted criteria for the validity and rigor of a mathematical 'proof' is decided by negotiation of school mathematics community. (c) There are dynamic relations between mathematical proof and empirical theory. We need to rethink the nature of mathematical proof and give appropriate consideration to the different types of proof related to the cognitive development of the notion of proof. 'proof' in school mathematics should be conceptualized in the broader, psychological sense of justification rather than in the narrow sense of deductive, formal proof 'proof' has not been taught in elementary mathematics, traditionally, Most students have had little exposure to the ideas of proof before the geometry. However, 'proof' cannot simply be taught in a single unit. Rather, proof must be a consistent part of students' mathematical experience in all grades, in all mathematics.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제4권1호
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• pp.63-73
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• 2000

The purpose of this paper is to address He possibility of the teaching of 'proof' in elementary mathematics, on the assumption that proof in school mathematics should be used in the broader, psychological sense of justification rather than in the narrow sense of deductive, formal proof. 'Proof' has not been taught in elementary mathematics, traditionally. Most students have had little exposure to the ideas of proof before the geometry. However, 'Proof' cannot simply be taught in a single unit. Rather, proof must be a consistent part of students' mathematical experience in all grades. Or educators and mathematicians need to rethink the nature of mathematical proof and give appropriate consideration to the different types of proof related to the cognitive development of a notion of proof.

• East Asian mathematical journal
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• 제24권5호
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• pp.527-545
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• 2008

One of the education purpose of the section "Figures" in the eighth grade is to develop students' deductive reasoning ability, which is basic and essential for living in a democratic society. However, most or middle school students feel much more difficulty or even frustration in the study of formal arguments for geometric situations than any other mathematical fields. It is owing to the big gap between inductive reasoning in elementary school education and deductive reasoning, which is not intuitive, in middle school education. Also, it is very burden for students to describe geometric statements exactly by using various appropriate symbols. Moreover, Usage of the same symbols for angle and angle measurement or segments and segments measurement makes students more confused. Since geometric relations is mainly determined by the measurements of geometric objects, students should be able to interpret the geometric properties to the algebraic properties, and vice verse. In this paper, we first compare and contrast inductive and deductive reasoning approaches to justify geometric facts and relations in school curricula. Convincing arguments are based on experiment and experience, then are developed from inductive reasoning to deductive proofs. We introduce teaching methods to help students's understanding for deductive reasoning in the textbook by using stepwise visualization materials. It is desirable that an effective proof instruction should be able to provide teaching methods and visual materials suitable for students' intellectual level and their own intuition.