Desenvolvimento de sequência didática para o ensino de Dispersões

Abstract

Given the difficulties and complexity of understanding the content of Dispersions, reported in the literature for high school students and, in order to assist in the process of teaching learning this content, this dissertation aimed to develop an educational product, the which is characterized by a didactic sequence that uses the Meaningful Learning Theory (developed by David Ausubel) - TAS - in its application stages. The target audience was a class, which contains 40 students from the 2nd grade of High School with full-time study, located in Fortaleza, Ceará. During the activities, the students' identities were preserved. The didactic sequence consists of five moments: the first is a questionnaire to survey students' previous knowledge along with a text; the second is an expository class (which was built from the results of the previous survey); The third is the use of simulators to fix and deepen knowledge. the fourth is the elaboration of concept maps; The fifth and last was the discussion of these concept maps and the elaboration of new ones. During the application of the first stage of the didactic sequence was observed, as a result, a lot of student participation in the initial discussions. Regarding the answers of the questionnaires, it was possible to notice that many students had difficulties related to the interpretation of mathematical data. It was also noticeable that some, besides presenting mathematical difficulties, were confused regarding concepts related to the words “homogeneous mixture” and “heterogeneous mixture”. In the second moment, the students were very participative during the explanation of the dispersion content, so that during the explanation they made statements remembering the questionnaire and the subject that was currently being explained. In the third moment the students showed excitement to participate in the online simulators. During the realization of the first simulator, John's Task, it was possible to notice some conceptual difficulties, but most of the class had good use. In the second simulator, it was also observed good performance and participation to work with different concentrations of substances and their respective interpretations. The third simulator, it was noticed that most of the class had difficulty to perform. This fact was possibly due to the presence of some calculations and interpretations necessary to complete the activity. In moment four, the difficulty in making the first concept maps was noticeable. The students had many doubts regarding the structure of these drawings. In the fifth moment, during the reconstruction of the concept maps, it was possible to perceive a better resourcefulness in the elaboration of the concept maps, so that the students were able to add more concepts, connect them through connectors and respect the conceptual hierarchy. It was possible to notice that the didactic sequence was very important in stimulating students to study Dispersions and also a good cognitive performance on the understanding of this content during the application stages. There is a highlight for the construction phase of the concept maps, as they make it possible to work on concepts and instrumentalize Meaningful Learning.