• Journal of Educational Research in Mathematics
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• v.19 no.3
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• pp.371-392
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• 2009

A lot of researches state mathematical justification is important. Specially, NCTM (2000) mentions that mathematical reasoning and proof should be taught every student from pre-primary school to 12 grades. Some of researches say elementary school students are also able to prove and justify their own solution(Lester, 1975; King, 1970, 1973; Reid, 2002). Balacheff(1987), Tall(1995), Harel & Sowder(1998, 2007), Simon & Blume(1996) categorize the level or the types of mathematical justification. We re-categorize the 4 types of mathematical justification basis on their studies; external conviction justification, empirical-inductive justification, generic justification, deductive justification. External conviction justification consists of authoritarian justification, ritual justification, non-referential symbolic justification. empirical-inductive justification consists of naive examples justification and crucial example justification. Generic justification consists of generic example and visual example. The results of this research are following. First, elementary school teachers in Korea respectively understand mathematical justification well. Second, elementary school teachers in Korea prefer deductive justification when they justify by themselves, while they prefer empirical-inductive justification when they teach students.

• Journal of Educational Research in Mathematics
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• v.9 no.1
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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.

• The Mathematical Education
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• v.53 no.4
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• pp.525-539
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• 2014

In this study, we suggest implications for teaching mathematical justification with analysis of 6th grade students' awareness of why they needed mathematical justification and their levels of mathematics justification in Algebra and Geometry. Also how their levels of mathematical justification were related to mathematic achievement. 96% of students thought mathematical justification was needed, the reasons were limited for checking their solutions and answers. The level of mathematical justification in Algebra was higher than in Geometry. Students who had higher mathematic achievement had higher levels of mathematical justification. In conclusion, we searched the possibility of teaching mathematical justification to students, and we found some practical methods for teaching.

• Journal of Educational Research in Mathematics
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• v.9 no.2
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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.

• Journal of the Korean School Mathematics Society
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• v.24 no.3
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• pp.261-282
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• 2021

This study identified the meaning of mathematical justification and its characteristics for middle school math gifted students. 17 middle school math gifted students participated in questionnaires and written exams. Results show that the gifted students recognized justification in various meanings such as proof, systematization, discovery, intellectual challenge of mathematical justification, and the preference for deductive justification. As a result of justification exams, there was a difference in algebra and geometry. While there were many deductive justifications in both algebra and geometry questionnaires, the difference exists in empirical justifications: there were many empirical justifications in algebra, but there were few in geometry questions. When deductive justification was completed, the students showed satisfaction with their own justification. However, they showed dissatisfaction when they could not deductively justify the generality of the proposition using mathematical symbols. From the results of the study, it was found that justification education that can improve algebraic translation ability is necessary so that gifted students can realize the limitations and usefulness of empirical reasoning and make deductive justification.

• Communications of Mathematical Education
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• v.26 no.1
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• pp.85-108
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• 2012

The comprehensive implication in justification activity that includes the proof in the elementary school level where the logical and formative verification is hard to come has to be instructed. Therefore, this study has set the following issues. First, what is the mathematical justification type shown in the Number and Operations, and Geometry? Second, what are the errors shown by students in the justification process? In order to solve these research issues, the test was implemented on 62 third grade elementary school students in D City and analyzed the mathematical justification type. The research result could be summarized as follows. First, in solving the justification type test for the number and operations, students evenly used the empirical justification type and the analytical justification type. Second, in the geometry, the ratio of the empirical justification was shown to be higher than the analytical justification, and it had a difference from the number and operations that evenly disclosed the ratio of the empirical justification and the analytical justification. And third, as a result of analyzing the errors of students occurring during the justification process, it was shown to show in the order of the error of omitting the problem solving process, error of concept and principle, error in understanding the questions, and technical error. Therefore, it is prudent to provide substantial justification experiences to students. And, since it is difficult to correct the erroneous concept and mistaken principle once it is accepted as familiar content that it is required to find out the principle accepted in error or mistake and re-instruct to correct it.

• ETRI Journal
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• v.25 no.3
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• pp.187-194
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• 2003

Delay testing has become an area of focus in the field of digital circuits as the speed and density of circuits have greatly improved. This paper proposes a new scan flip-flop and test algorithm to overcome some of the problems in delay testing. In the proposed test algorithm, the second test pattern is generated by scan justification, and the first test pattern is processed by functional justification. In the conventional functional justification, it is hard to generate the proper second test pattern because it uses a combinational circuit for the pattern. The proposed scan justification has the advantage of easily generating the second test pattern by direct justification from the scan. To implement our scheme, we devised a new scan in which the slave latch is bypassed by an additional latch to allow the slave to hold its state while a new pattern is scanned in. Experimental results on ISCAS'89 benchmark circuits show that the number of testable paths can be increased by about 45 % over the conventional functional justification.

• Journal of Korean Elementary Science Education
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• v.29 no.4
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• pp.414-426
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• 2010

For this study, inquiry-based learning program was developed for promoting elementary students' scientific justification activities based on their uses of scientific evidences. The program was applied to the 5th grade science class to examine the types of evidences and major features of scientific justification activities. Analysis of the data showed that the evidences used by students were classified into knowledge-based evidence, experience-based evidence and authority-based evidence. As for students' justification features, this study reports three major cases: a case evolving evidence and justification to become more valid and logical, as inquiry activities progressed, other case maintaining less valid and illogical evidence and justification, and final case revealing passive and reluctant participation in the inquiry activities. Overall, students' participation in scientific justification process became more valid and relevant, while there were some students who were unable to make the relevant relations between evidences and claims they made. The educational implications were discussed to consider more effective ways to improve the scientific classroom environment through social knowledge construction.

• Journal of Elementary Mathematics Education in Korea
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• v.15 no.2
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• pp.417-435
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• 2011

Mathematical justification is essential to assert with reason and to communicate. Students learn mathematical justification in 8th grade in Korea. Recently, However, many researchers point out that justification be taught from young age. Lots of studies say that students can deduct and justify mathematically from in the lower grades in elementary school. I conduct questionnaire to know awareness and steps of elementary school students and middle school students. In the case of 9th grades, the rate of students to deduct is highest compared with the other grades. The rease is why 9th grades are taught how to deductive justification. In spite of, however, the other grades are also high of rate to do simple deductive justification. I want to focus on the 6th and 5th grades. They are also high of rate to deduct. It means we don't need to just focus on inducing in elementary school. Most of student needs lots of various experience to mathematical justification.

• Korean Journal of Logic
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• v.22 no.1
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• pp.125-150
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• 2019

A coherence theory is adequate as a theory of justification only when justification as conceived by the theory is truth-conducive. But it is not clear how coherentist justification is truth-conducive. This is the alleged truth-conduciveness problem of coherentism. In my 2017 paper, I argued that a certain version of the coherence theory, namely a Sellarsian coherence theory combined with the deflationary conception of truth, can cope with this problem. Against this claim, Kiyong Suk argues in his recent paper that my proposed solution fails on the grounds that there is no practical way of distinguishing between intersubjective justification and objective justification. The purpose of this paper is to clarify my view by way of explaining why Suk's criticism is not correct. In particular, I argue that his criticism is based on a wrong assumption, namely that for one to be objectively justified in believing something, one's justification must be qualitatively transformed into the status of having objective justification from the status of having intersubjective justification.