Contextualizing practices across epistemic levels in the chemistry laboratory

Abstract

ABSTRACT:The process of construction of meanings for the concepts of concentration and neutralization is explored in terms of contextualizing practices (Lemke, 1990, Talking Science. Language, Learning and Values, Norwood, NJ: Ablex) creation of meanings through connections established among actions and their context. This notion is expanded to include the connections established among concepts and their context of use, a solving problem task in a laboratory. The purpose is to document the process of meaning construction for these concepts and their transformation from mere terms into decisions and practical actions in a chemistry laboratory. We sought to combine this analysis with an epistemological focus, examining the relative epistemic status of the contextualizing practices. The conversations and actions of four grade 10 students and their teacher (second author) were recorded while solving an open task: to find the concentration of an HCl solution. The results show a progression in the process of contextualization, from an initial inability to use the concepts as part of the resources to complete the titration task, to the transformation of definitions into shared meaningful concepts that allow to take actions,

Scaffolded Problem‐solving in the Physics and Chemistry Laboratory: Difficulties hindering students’ assumption of responsibility

“…In the next excerpt, from Task 3, the layout of the transcription in columns allows for an appreciation of the contributions of each student. The students call the teacher for help, because they cannot progress in a problem perceived as having "two unknowns", the concentration of the acid, and that of the base, because they did not understand that they had to decide the last by themselves (Jiménez-Aleixandre & Reigosa, 2006 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 what the students perceive as two unknowns, telling them that they could choose the amount of NaOH (671), and the equivalence one mol / one mol, making part of the concept of neutralization. This support from the teacher is interpreted as being in the ZPD because he…”

Interações Discursivas E Práticas Epistêmicas Em Salas De Aula De Ciências

“…Quanto a isso, o interesse por aspectos epistêmicos na Educação em Ciências tem gerado diferentes propostas de ferramentas para análise do movimento epistêmico dos estudantes e do suporte dado pelos professores na configuração desses movimentos, bem como agendas de pesquisa nessa direção (SANDOVAL, 2001;KELLY;TAKAO, 2002;TAKAO;KELLY, 2003;KELLY;DUSCHL, 2002;SANDOVAL;MORRISON, 2003;SANDOVAL;RESIER, 2004;SANDOVAL, 2005;WICKMAN, 2004;KELLY, 2005, LIDAR;LUNDQVIST;OSTMAN, 2005;JIMÈNEZ-ALEIXAN-DRE;REIGOSA, 2006).…”

Desafíos planteados por las actividades abiertas de indagación en el laboratorio: articulación de conocimientos teóricos y prácticos en las prácticas científicas

“…Estos autores identifican las dificultades del alumnado para conectar los recursos materiales y cognitivos con los conceptos relevantes, debido a que carecen de un contexto adecuado en el que situar sus acciones, por ser la tarea muy difícil para el nivel educativo en el que se realiza (4.º de ESO). La idea de contextualización pretende proporcionar un marco que subraye la relevancia de los conocimientos teóricos en los trabajos prácticos (Jiménez Aleixandre y Reigosa, 2006). La necesidad de tener en cuenta los aspectos epistémicos y teóricos en la indagación ha sido señalada también por Osborne (2014), quien critica que la indagación ha prestado poca atención a estos aspectos frente a los empíricos.…”

“…A partir de la división en episodios, se elaboró una rúbrica que comprende cinco categorías que representan las prácticas de contextualización llevadas a cabo por los participantes. Estas categorías, adaptadas de las propuestas por Jiménez Aleixandre y Reigosa (2006), se construyen en interacción con los datos y representan el uso que los participantes hacen de su conocimiento (químico, biológico, empírico y prácticas científicas). La rúbrica se resume en la tabla 1 y las categorías se detallan en los resultados.…”