Identifying and improving students' mental models of tooth decay

The aims of this study were to identify the initial mental models of tooth decay among a sample of 15-16 year-old Spanish students, and then to analyse changes in these models following the students’ participation in a teaching sequence on this topic. The study focuses on the analysis of two tasks that formed part of a pretest/ post-test design whose aim was to determine whether students could provide an adequate explanation of the problem of dental caries. Mental models were identified through an iterative process that combined an examination of the nature of the concept in question with an analysis of students’ responses. Five mental models of tooth decay were identified. Three of them were associated with a single active agent (the tooth, food or microscopic living organisms). The fourth model included sugar plus a second active agent, while the active agent in the fifth model was acids. We also identified four mechanisms, which were not exclusive to any one model. The results showed an evolution in students’ explanatory models of tooth decay following their participation in the teaching sequence. Initially, the majority of students used simple models involving a single active agent, whereas by the end of the teaching sequence the majority of them were employing the most advanced models. However, formulating the mechanism through which tooth decay develops remains a complex task for students, particularly as regards understanding that the interactions which produce the active agent and its action upon a tooth are chemical reactions.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Study of SiPM segmentation in ToF-PET from the optical perspective

Introduction of SiPM sensor in positron emission tomography (PET) technique has allowed the use of time-of-flight (ToF) information, which improves the imaging technique performance. However, there is still a lot of room for improvement. One approach to increase the image resolution, consists on segmenting the SiPM area into smaller areas and apply an algorithm to recover the maximum possible information. In the literature, it has been shown that this approach can increase the coincidence time resolution (CTR). Here, we study how segmenting the sensor area into smaller sensors affects the time resolution from an optical perspective. In order to accomplish this, we simulated different segmentations and studied how the segmentation a↵ects the CTR of the system. Results show that the CTR doesn’t degrade significantly when segmenting the sensor in a few channels. Therefore, it can be expected an increase on the total CTR if a increase on the electronics performance can be achieved

Enseñanza y aprendizaje de la física a través de la lectura del Quijote en 4.º de ESO : las leyes de Newton y la aventura de los molinos de viento

En este trabajo se presenta el efecto que produce en el aprendizaje de temas de dinámica, respecto a una metodología tradicional de nivel de 4.º de ESO (16 años), el uso de una metodología innovadora basada en la lectura de la famosa aventura de los molinos de viento del Quijote, donde el alumno juega un papel activo, plantea y resuelve sus propios problemas científicos y se convierte en el verdadero protagonista de su aprendizaje. Los resultados obtenidos sugieren que la metodología basada en la lectura es capaz de producir avances, que deben considerarse modestos, en el aprendizaje del concepto de fuerza y de las leyes de Newton. Entre las causas que justifican la mejora en los resultados de aprendizaje se encuentra la mayor implicación del alumno en este tipo de tareas, causada por la motivación que produce el empleo en el aula de una metodología de trabajo diferente a la usual.We present in this paper a new methodology focused on the learning of Dynamics topics through the reading of the famous Quixote's Windmills Adventure. We compare the effect produced in learning by this innovative methodology versus conventional methods in 10th grade students (16 years old). Pupils are given an active role in this new methodology: they become the main protagonists of learning because scientific problems have to be formulated and solved by them. The results obtained suggest that this reading-based methodology is able to produce moderate progress in the learning of the force concept and the Newton's laws. The improvement of the results may be justified by a major implication of the pupils in that type of assignments and the motivation element that produces the use of a different methodology in the class

Enseñando física y química con ideas quijotescas

Segundo Premio Nacional de Innovación Educativa 2006Proyecto para alumnos de 4õ de ESO que consiste en aplicar la Física y la Química a situaciones cotidianas del libro Don Quijote de la Mancha y a la vez practicar la lectura. Para los alumnos cada capítulo tiene un título, breve resumen, concepto científico y actividad de aplicación. Y para los profesores una guía didáctica y de contenidos.MadridBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín 5 -3 Planta; 28014 Madrid; Tel. +34917748000; [email protected]

Teaching students about chemical elements using daily-life contexts

Learning the names and symbols for chemical elements is a task that students often find dull, although it is of crucial importance for understanding chemistry. In this respect, the use of games or similar play activities could make the learning experience more enjoyable. This paper presents the results of a study in which two tasks involving play (TIPs) and based on daily-life contexts (football and the home) were used to teach the names and symbols of chemical elements. The experimental group comprised 38 year-10 students who studied this topic through a teaching unit built around the TIPs. A control group of 67 year-10 students followed a traditional teaching approach to the same topic. The effectiveness of the TIPs was assessed using three items, administered pre- and post-test, that explored students’ knowledge about metallic and non-metallic elements and their ability to identify them in their everyday environment. Following the TIP-based teaching unit, students in the experimental group gave a higher percentage of appropriate answers, with the Wilcoxon test indicating significant post-test differences for all three items. However, the Kolgomorov-Smirnov test indicated that the experimental and control groups only differed significantly at post-test in their ability to give the names and symbols of non-metals, with the experimental group performing better. Memorising the names and symbols of chemical elements is a complex task for students, and identifying their presence in everyday environments appears to be particularly difficult. However, the results suggest that the use of TIPs linked to daily-life contexts could help students with their learning of this topic.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Proyecto ‘I+D Excelencia’ EDU2013-41952-

Como muestra un botón : un ejemplo de trabajo práctico en el área de ciencias de la naturaleza en el segundo curso de educación secundaria obligatoria

Presentamos, en este artículo, un ejemplo de trabajo práctico en ciencias de la naturaleza en la etapa de educación secundaria obligatoria (13-14 años). El objetivo de este trabajo práctico es estudiar los errores conceptuales que cometen los alumnos al describir y clasificar cualquier tipo de elementos. Para ello, hemos elegido como elementos de trabajo, en clase y en el laboratorio, botones. Nuestra meta ha sido conseguir un trabajo práctico de acuerdo con los principios de una educación abierta, activa y participativa. De esta forma, los alumnos usarán la metodología científica unida al aprendizaje significativo.We present in this paper an example of practical work in Natural Sciences at secondary education level (13-14 years old). The aim of this practical work is to study the conceptual mistakes that the students make when they describe and classify any type of elements. We have chosen as elements of work, at the classroom and the laboratory, buttons. Our goal has been to achieve a type of practical work according to the educational principles of openness, activity and participation. In this way the students will get used to the scientific methodology closely linked to significative learning

Identification of students' mental models about the milk transformation in yogurt

A review of the scientific literature reveals that there are still few researches on the conceptions of secondary school students about chemical reactions involving microorganisms, especially those related to the mental models that students use in their explanations. This paper describes a study concerning the different mental models related to the milk transformation into yogurt with 83 students from a Spanish secondary school of 8th and 9th grade (13-16 years) developed in the framework of a research that intends to use the elaboration of this product as a context for the teaching and learning of chemical reactions through modeling approaches. In order to identify the mental models of the students, in this paper we consider the milk transformation into yogurt as a process in which its main components are: the entities involved (milk and bacteria), the interaction between them and the result (yogurt). A simplified school model of this process would involve students considering that bacteria use the sugar in milk to transform it into lactic acid through a chemical reaction to obtain the necessary energy. Using this scheme in interaction with the students' answers, the underlying mental models were identified. Although almost half of the students showed great difficulties explaining the process, five models have been identified. Students often consider the milk transformation into yogurt primarily as a physical process of agglutination or change of state. These models are far from a school model of reference in which the bacteria have a fundamental role in the transformation of milk into yogurt by a chemical reaction.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Lectura y literatura didáctica moral: una lectura comparada de tres fábulas mitológicas de Félix María de Samaniego y sus implicaciones didácticas

[Resumen] En este trabajo se analizan tres fábulas mitológicas de Samaniego, comparadas con los textos análogos de otros fabulistas como Esopo, Babrio, Fedro o La Fontaine. Las origina- les versiones del escritor español nos sirven para reflexionar sobre las posibilidades creati- vas de la lectura en el aula mediante el ejercicio de la comparación y de la emulación.[Abstract] In this study we analyse three mythic fables written by Samaniego, compared with the similar texts by Aesopus, Babrius, Phaedrus and La Fontaine. The original versions of the Spanish writer help us to reflect on the creative possibilities of attentive reading at school and tasks such as comparisons of texts and emulation