• Journal of Educational Research in Mathematics
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• v.19 no.1
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• pp.81-98
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• 2009

This study analyzed the types of quantitative reasoning and the characteristics of representation in order to figure out the characteristics of quantitative reasoning of the sixth graders. Three students who used quantitative reasoning in solving problems were interviewed in depth. Results showed that the three students used two types of quantitative reasoning, that is difference reasoning and multiplicative reasoning. They used qualitatively different quantitative reasoning, which had a great impact on their problem-solving strategy. Students used symbolic, linguistic and visual representations. Particularly, they used visual representations to represent quantities and relations between quantities included in the problem situation, and to deduce a new relation between quantities. This result implies that visual representation plays a prominent role in quantitative reasoning. This paper included several implications on quantitative reasoning and quantitative approach related to early algebra education.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.4
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• pp.601-625
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• 2016

In this study, I hoped to reveal the understanding of pre-service elementary teachers about proportional reasoning and the traits of proportional reasoning strategy used by pre-service elementary teachers. The results of this study are as follows. Pre-service elementary teachers should deal with various proportional reasoning tasks and make a conscious effort to analyze proportional reasoning task and investigate various proportional reasoning strategies through teacher education program. It is necessary that pre-service elementary teachers supplement the lacking tasks such as qualitative reasoning and distinction between proportional situation and non-proportional situation. Finally, It is suggested to preform the future research on teachers' errors and mis-conceptions of proportional reasoning.

• Journal of Elementary Mathematics Education in Korea
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• v.19 no.4
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• pp.457-484
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• 2015

This study aims to investigate an approach to teach proportional reasoning in elementary mathematics class by analyzing the proportional strategies the students use to solve the proportional reasoning tasks and their percentages of correct answers. For this research 174 sixth graders are examined. The instrument test consists of various questions types in reference to the previous study; the proportional reasoning tasks are divided into algebraic-geometric, quantitative-qualitative and missing value-comparisons tasks. Comparing the percentages of correct answers according to the task types, the algebraic tasks are higher than the geometric tasks, quantitative tasks are higher than the qualitative tasks, and missing value tasks are higher than the comparisons tasks. As to the strategies that students employed, the percentage of using the informal strategy such as factor strategy and unit rate strategy is relatively higher than that of using the formal strategy, even after learning the cross product strategy. As an insightful approach for teaching proportional reasoning, based on the study results, it is suggested to teach the informal strategy explicitly instead of the informal strategy, reinforce the qualitative reasoning while combining the qualitative with the quantitative reasoning, and balance the various task types in the mathematics classroom.

• School Mathematics
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• v.14 no.4
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• pp.445-468
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• 2012

This study is tried in order to link informal arithmetic reasoning to formal algebraic reasoning. In this study, we investigated elementary school student's non-formal algebraic reasoning used in algebraic problem solving. The result of we investigated algebraic reasoning of 839 students from grade 1 to 6 in two schools, Korea, we could recognize that they used various arithmetic reasoning and pre-formal algebraic reasoning which is the other than that is proposed in the text book in word problem solving related to the linear systems of equation. Reasoning strategies were diverse depending on structure of meaning and operational of problems. And we analyzed the cause of failure of reasoning in algebraic problem solving. Especially, 'quantitative reasoning', 'proportional reasoning' are turned into 'non-formal method of substitution' and 'non-formal method of addition and subtraction'. We discussed possibilities that we are able to connect these pre-formal algebraic reasoning to formal algebraic reasoning.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2006.06a
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• pp.125-130
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• 2006

원활한 의사소통을 위해서는 문장들을 연결하여 흐름을 조직하고 말로 산출하고 전체적인 의미를 파악할 수 있어야 한다. 이야기는 이러한 문장들이 연결되어있는 것으로, 종속적이거나 나열적인 이야기 특성은 의사소통장애인의 이야기 이해와 산출의 수행에 영향을 미칠 수 있다. 본 연구에서는 이야기 특성에 따른 유창성 실어증환자의 이야기 이해 및 산출의 능력을 알아보고, 이해과제 수행이 산출과제에 미치는 영향을 분석해보았다. 이야기 종류로는 시간적 나열 이야기와 인과적 관계 이야기, 유머가 있는 이야기를 사용하였으며, 사실적 정보, 텍스트 추론, 빠진 정보추론 등 세 가지의 이해과제를 통하여 이해 능력을 측정하였다. 산출능력은 이해과제 전과 후에 CIU 비율로 질적인 측면을 측정하고, 분당어절 수를 이용하여 양적인 측면을 분석하였다. 그 결과 이해측면은 세 가지 이야기 모두 사실적 정보에 대한 이해 능력이 상대적으로 좋았으며, 오류의 형태는 추론오류가 가장 많이 나타났다. 산출에서는 인과적 관계이야기에서의 CIU 비율이 가장 높았고, 이해과제 전, 후의 차이를 비교한 결과, CIU 비율은 변화하지 않았으나, 분당 어절수에서는 증가하고 있음을 보여주었다. 이야기의 종류에 따라서 유창성 실어증화자의 산출과제의 수행수준은 다르게 나타났다. 그리고 이해과제의 수행이 산출과제에서 양적인 증가는 가져왔으나 질적인 수준에는 아무런 영향을 미치지 않았다.

• Proceedings of the Korea Society for Simulation Conference
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• 2002.05a
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• pp.43-49
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• 2002

본 연구는 첨단 신호 시스템 알고리즘의 최적해를 구하는 문제를 기호적 시뮬레이션 기법으로 해결하기 위한 방법론을 제시한다. 최근 지능형 교통 시스템의 일환으로 최적화 된 교통신호를 생성하기 위한 신호제어기법들이 많이 개발되었다. 하지만 이러한 신호제어기법은 복잡한 교통환경에서 신호제어 변수간의 다양한 상호작용의 모든 해를 제공할 수 없는 한계를 지닌다. 한편 기호적 시뮬레이션 기법은 발생 가능한 모든 사건과 시간관계를 자동 생성시킴으로써 동적으로 변화하는 다양한 교통환경에 대해서 신호제어 변수간의 모든 시간관계를 추론해 낼 수 있는 장점을 지닌다. 하지만 기호적 시뮬레이션을 이용한 모델링에 있어서 교통량과 같은 양적인 요소들의 기호적 표현에는 어려움이 따른다. 따라서 본 논문에서는 교통량과 같은 양적인 요소들을 시간에 따른 변화량으로 해석하여 첨단 신호 시스템 알고리즘의 최적해를 구하는 문제에 접근한다. 이를 위해 국내 첨단 신호 시스템을 대상으로 신호제어 전략에 필요한 양적 요소를 검토하고, 이러한 양적 요소를 시간에 따른 변화량으로 해석하여 모델링 하고, 기호적 시뮬레이션 실험을 수행하여 최적신호 제어 알고리즘을 생성한다.

• Journal of Educational Research in Mathematics
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• v.27 no.1
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• pp.23-49
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• 2017

This study examined two current learning models for covariational reasoning(Carlson et al.(2002), Thompson, & Carlson(2017)), applied the models to teaching two $9^{th}$ grade students, and analyzed the results according to the types of graphs(a quantitative graph or qualitative graph). Results showed that the model of Thompson and Carlson(2017) was more useful than that of Carlson et al.(2002) in figuring out the students' levels in their quantitative graphing activities. Applying Carlson et al.(2002)'s model made it possible to classify levels of the students in their qualitative graphs. The results of this study suggest that not only quantitative understanding but also qualitative understanding is important in investigating students' covariational reasoning levels. The model of Thompson and Carlson(2017) reveals more various aspects in exploring students' levels of quantitative understanding, and the model of Carlson et al.(2002) revealing more of qualitative understanding.

• School Mathematics
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• v.18 no.4
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• pp.819-838
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• 2016

This research analyzed proportional reasoning abilities of the 5th grade students who learned only the basis of ratio and rate and 6th grade students who also learned proportion and cross product strategy. Data were collected through the proportional reasoning tests and the interviews, and then the achievement of the students and their proportional reasoning strategies were analyzed. In the light of such analytical results, the conclusions are as follows. Firstly, there is not much difference between 5th and 6th grade students in the achievement scores. Secondly, both 5th and 6th graders are less familiar with the geometric, qualitative and comparisons tasks than the other tasks. Thirdly, not only 5th graders but also 6th graders used informal strategies much more than the formal strategy. Fourthly, some students can't come up with other strategies than the cross product strategy. Finally, many students have difficulties in discerning proportional situation and non-proportional situations. This study provided suggestions for improving teaching proportional reasoning in elementary schools in Korea as follows: focusing on letting students use their informal strategies fluently in geometric, qualitative, and comparisons tasks as well as algebraic, quantitative, and missing value tasks focusing on the concept of ratio and proportion instead of enforcing the formal strategy.

• Journal of Educational Research in Mathematics
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• v.25 no.1
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• pp.21-58
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• 2015

The aim of this study is to look into the didactical background for teaching proportional reasoning in elementary school mathematics and offer suggestions to improve teaching proportional reasoning in the future. In order to attain these purposes, this study extracted and examined key ideas with respect to the didactical background on teaching proportional reasoning through a theoretical consideration regarding various studies on proportional reasoning. Based on such examination, this study compared and analyzed textbooks used in the United States, the United Kingdom, and South Korea. In the light of such theoretical consideration and analytical results, this study provided suggestions for improving teaching proportional reasoning in elementary schools in Korea as follows: giving much weight on proportional reasoning, emphasizing multiplicative comparison and discerning between additive comparison and multiplicative comparison, underlining the ratio concept as an equivalent relation, balancing between comparisons tasks and missing value tasks inclusive of quantitative and qualitative, algebraic and geometrical aspects, emphasizing informal strategies of students before teaching cross-product method, and utilizing informal and pre-formal models actively.

• Journal of Educational Research in Mathematics
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• v.23 no.4
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• pp.505-516
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• 2013

The purpose of this paper is to analyse the essence of proportional reasoning and to analyse the contents of the textbooks according to the mathematics curriculum revised in 2007, and to seek the direction for developing the proportional reasoning in the elementary school mathematics focused the task variables. As a result of analysis, it is found out that proportional reasoning is one form of qualitative and quantitative reasoning which is related to ratio, rate, proportion and involves a sense of covariation, multiple comparison. Mathematics textbooks according to the mathematics curriculum revised in 2007 are mainly examined by the characteristics of the proportional reasoning. It is found out that some tasks related the proportional reasoning were decreased and deleted and were numerically and algorithmically approached. It should be recognized that mechanical methods, such as the cross-product algorithm, for solving proportions do not develop proportional reasoning and should be required to provide tasks in a wide range of context including visual models.