Uso y análisis de las representaciones iónicas del ecosistema en los libros de texto durante la enseñanza y el aprendizaje en 2º ESOun estudio de caso

Résumé

The aim of this thesis is to analyse the images and their usage in textbooks of the second year of Obligatory Secondary Education (Escuela Secundaria Obligatoria, ESO). The study of the aforementioned images has been carried out with the didactic purpose of emphasising their contribution to the illustration of content in teaching and learning about the ecosystem. In order to demonstrate their usage, the teacher’s conceptions of instructional strategies of teaching and the students’ conceptions of the ecosystem will be explored, identifying the possible impact of these images on the change or development of students’ conceptions of the ecosystem. The analysis was conducted based on a Case Study-oriented qualitative model, and the data was elicited from four students, their teacher and four textbooks of the top-seller Editorials used in the second year of ESO. It is important to point out that the subjects of this study use only one of the four textbooks studied. Nevertheless, in order to have a contrast referent and to reveal uniformity or diversity between them, other three textbooks were included in the analysis. The data was collected during a three-month-period via classroom observations, interviews, recordings, questionnaires and a document review of the mentioned textbooks, allowing information-triangulation at the different stages of the analysis. The different categories used in the data analysis form three pillars which constitute the basis of the study: Pedagogical Content Knowledge (PCK), conceptual change and the role of images in textbooks. The categories implemented in the analysis of the images were partially obtained from a validated instrument by Perales y Jimenez (2002), and were adapted to the objective of this study. So as to understand the framework of instructional strategies in teaching the ecosystem, a component of PCK, we embrace the ideas proposed by Magnusson, Krajcik and Borko (1999), along with the ones of Gess-Newsome (2015) in an inclusive way, however, maintaining a certain distance at the same. On the other hand, the conceptual change observed in the students is addressed drawing on Posnert et al. (1982). The processing of images, at a greater extent is focused on the referent of Science Teaching Didactics. The results show that teacher’s conceptions of the instructional strategies used in learning about and teaching the ecosystem can be classified by an iconographic lack of awareness impregnated with a traditional approach. We also found that the use that the teacher makes of the images, focusing on their identification function (mnemonics), partially facilitated the development of the students’ concepts of the ecosystem; nevertheless, the prevalence of the simplistic model in illustrating the food chain should be highlighted. From this perspective, the absence of activities which foster critical thinking can be put down to the teacher’s lack of pedagogical, didactic and iconic knowledge, which can limit the development of visual skills in students, as the successful development of these skills depends on using these images favourably. In addition, we found that students’ learning strategies and the teacher’s instructional strategies combined with the theoretical basics, allow the configuration of Pedagogical Content Knowledge of the Ecosystem (PCK-Ec), which could be used as a referent for self-evaluation for teachers. With respect to the represented images in the textbook, which is the most common pedagogical, didactic and curricular tool for teachers (Cuéllar, Pérez y Quintanilla, 2005) it has been demonstrated that out of the 241 analysed images, 96% excludes the human being from the representation of the ecosystem, 49% presents an iconicity with a tendency to photography, 49% shows an image of science as absolute truth, 51% were accompanied by nominative captions and 45% with relational captions. Moreover, all four textbooks, to a greater or lesser extent, establish favourable links to the learning of the ecosystem. Based on the obtained results, a well-grounded proposal for the teaching of the ecosystem from the humankind’s conservative and integrative perspective as something inherent to the functioning of the ecosystem emerges, in some way starting with redesigning the images of textbooks. In conclusion, images are complex representations, thus an adequate intervention of the teacher as a mediator in their interpretation of these images is needed. As a result, there is an immediate need to develop the teachers’ and students’ visual competences.