This paper presents a pedagogical experiment with parallel groups through which the effectiveness of the cognitive apprenticeship model of dealing with the teaching topic Carboxylic acids and their derivatives was compared with the traditional approach to the elaboration of this topic. This experiment featured the participation of 241 students aged 17, attending their third year of grammar school, natural sciences stream. The experimental group consisted of 118 students, whereas the control group was made up of 123 students. Within the framework of the experiment, a pre-test consisting of items that resembled regular textbook items was used as an instrument for checking how balanced the previously acquired knowledge concerning the teaching topic Carboxylic acids and their derivatives of the students in the two groups was. A post-test was used as an instrument for comparing the effectiveness of the two approaches, and it mostly consisted of items that required the application of the knowledge concerning the teaching topic Carboxylic acids and their derivatives in solving real-life problems. In the pre-test, no statistically significant difference in the overall percentage of correct answers given by the two groups of students was established. In the post-test, the students from the experimental group scored a statistically significant higher percentage of correct answers compared to the students from the control group. On the basis of this, it can be concluded that the applied cognitive apprenticeship approach has the potential to improve the level of students’ understanding of the concepts from the topic Carboxylic acids and their derivatives, as well as the students’ ability to apply the knowledge on the examples from real life.

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The aim of this research was to investigate whether pupils aged 13, at the end of their first year of studying chemistry, are capable of perceiving the macroscopic and the submicroscopic level of the previously learned contents on chemical reactions, and whether they relate them to the chemical equations (the symbolic representation). Another aim was to establish how much demonstration experiments contribute to a better linking of the mentioned levels. The research featured 69 pupils of the seventh grade from three primary schools. The pre-test was conducted, following which experiments were demonstrated, and the post- -testing was carried out in the end. After the intervention, a total of 12 pupils were interviewed about which aspects of chemical reactions they thought of based on the chemical equations. A statistically significant difference in two out of five requirements of the post-test, compared to the pre-test, indicate that the demonstration experiments may contribute to a better linking of three levels of representing chemical reactions. However, when one compares the pupils? answers in the test and in the interview, it can be observed that the correct answers in the test are not always based on understanding the concepts in connection with the chemical reaction. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 179048: The Theory and Practice of Science in Society: Multidisciplinary, Educational and Intergenerational Perspectives]

The aim of this research was to explore the effects of two approaches, designated as the historical and the contemporary one, on the level of students' understanding of the properties and the practical use of gases. Our research hypothesis was that the historical context of the discovery of gases and the study of their properties would deepen students' understanding of the properties and the practical use of gases more than the contemporary context. A total of 129 students attending the eighth grade of primary school, aged 14, took part in the research project. After taking a pre-test, the students were divided into two groups (A and B respectively), equal in terms of their test scores. Group A (63 students) was exposed to the historical approach, whereas group B (66 students) was exposed to the contemporary approach. The students from group A individually dealt with a text that presented various episodes from the scientific-research work of Joseph Priestley, whereas the students from group B dealt with a text pertaining to the properties and the use of gases in contemporary society. Having been exposed to different approaches, all the students did a post-test. No statistically significant difference was established between the overall results of the students who had been exposed to the historical approach and those exposed to the contemporary approach, and the research hypothesis was rejected. However, one statistically significant better score in one of the post-test items in group A may be connected with the influence of the corresponding episode from the history of science.