A dilemma that underlies an existence proof in geometry

Proving an existence theorem is less intuitive than proving other theorems. This article presents a semiotic analysis of significant fragments of classroom meaning-making which took place during the class-session in which the existence of the midpoint of a linesegment was proven. The purpose of the...

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Detalhes bibliográficos
Autores: Samper, Carmen, Perry, Patricia, Camargo, Leonor, Sáenz-Ludlow, Adalira, Molina, Óscar
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2016
País:Colombia
Recursos:Universidad de los Andes
Repositorio:Séneca: repositorio Uniandes
Idioma:inglés
OAI Identifier:oai:repositorio.uniandes.edu.co:1992/32353
Acesso em linha:http://hdl.handle.net/1992/32353
http://funes.uniandes.edu.co/9439/
Access Level:acceso abierto
Palavra-chave:Geometría (matemáticas superiores)
Procesos de justificación
Educación / Licenciaturas
Descrição
Resumo:Proving an existence theorem is less intuitive than proving other theorems. This article presents a semiotic analysis of significant fragments of classroom meaning-making which took place during the class-session in which the existence of the midpoint of a linesegment was proven. The purpose of the analysis is twofold. First follow the evolution of students¿ conceptualization when constructing a geometric object that has to satisfy two conditions to guarantee its existence within the Euclidean geometric system. An object must be created satisfying one condition that should lead to the fulfillment of the other. Since the construction is not intuitive it generates a dilemma as to which condition can be validly assigned initially. Usually, the students¿ spontaneous procedure is to force the conditions on a randomly chosen object. Thus, the second goal is to highlight the need for the teacher¿s mediation so the students understand the strategy to prove existence theorems. In the analysis, we use a model of conceptualization and interpretation based on the Peircean triadic SIGN.