Conceptual errors (mainly in Physics and Chemistry), constitute a serious problem, not only for their extension (they affect a large number of students from all countries and of any educational level) but also because they frequently respond to alternative ideas on basic scientific concepts, which are very difficult to change, even when they are explicitly taken into account in teaching. All this contributed to a very abundant investigation carried out in the 80s about the alternative conceptions of the students. This work is part of this investigation and is probably the first one in Spain about misconceptions in Physics and Chemistry. This line of research has had great historical importance, not only for its intrinsic relevance but also for its contribution to the development of the constructivist postulates in the teaching and learning of science and Science Education as a specific body of knowledge, with the characteristics of a scientific discipline. The work focuses on two fundamental questions, which are intended to respond: 1. What are the main causes of the great abundance and persistence of conceptual errors in Physics and Chemistry committed by students and also by some teachers? 2. How to achieve an effective influence in overcoming the problem of conceptual errors in Physics and Chemistry? The answer to the first question constitutes the first part of the thesis, which is guided by a first hypothesis according to which the persistence of conceptual errors is mainly due to incorrect didactic orientations, essentially consisting of not taking students’ alternative ideas into account, nor, above all, their usual methodology of work, which we have called the methodology of "common sense" or "superficial methodology”. Regarding the second question, its answer is associated with a second hypothesis whose testing is addressed in the second part of the work. It consists of affirming that the effective overcoming of the conceptual errors and the change or evolution of the alternative ideas that originate them towards other ones closer to current scientific concepts, can be achieved through a didactic orientation that poses learning as a construction of knowledge following similar guidelines to those of scientific work. After the theoretical foundation of the two stated hypotheses, we proceed to the derivation of a series of consequences susceptible of being tested experimentally, describing in detail the designs prepared for it, which include numerous examples of conceptual errors, various questionnaires explicitly prepared for the detection of certain alternative ideas, analysis of textbooks, assessment tests, questionnaires on methodological aspects, etc. The results and conclusions obtained with this multiple-focus design, amply confirm both hypotheses. In total, more than 3,500 students from all educational levels (from Basic Education to University), 300 teachers in training and 200 teachers in service (all of them of Physics and Chemistry) have been involved. The work is completed with a series of annexes that, to avoid unnecessary meandering, are included at the end of it. Among them, it is worth highlighting the annex II which shows a wide collection with more than 60 questions specifically designed for the detection and solving of certain misconceptions that affect some basic concepts of Physics and Chemistry.
