Uporaba demonstracijskih eksperimentov pri pouku kemije v osnovnih in srednjih šolah

• Main Author: Vinko, Luka
• Other Authors: Devetak, Iztok
• Format: Master Thesis
• Language: Slovenian
• Published: 2019
• Subjects: osnovna šola; elementary school; Malo; Neko; sami
• Online Access: https://repozitorij.uni-lj.si/IzpisGradiva.php?id=107535; https://repozitorij.uni-lj.si/Dokument.php?id=118372&dn=; https://plus.si.cobiss.net/opac7/bib/12377929?lang=sl

Kemija je eksperimentalna veda, ki uporablja eksperiment kot eno glavnih orodij preučevanja. Laboratorijsko in drugo praktično delo sta tako esencialna tudi pri kemijskem izobraževanju, kar kažejo tudi učni načrti za kemijo tako v osnovi kot srednji šoli, ki izhajajo predvsem iz dejavnosti na makroskopski ravni. Kadar govorimo o praktičnem delu, govorimo o dejavnostih, pri katerih učenci sami upravljajo s snovmi, predmeti, ali pa opazujejo demonstracijske eksperimente. Za demonstracijske eksperimente je značilno, da jih izvaja učitelj ali različni strokovnjaki, ki lahko učencem neko dejavnost demonstrirajo najbolj kakovostno, učenci pa pri tem neposredno sodelujejo in usvajajo znanje na izkustven način. Prednost demonstracijskih eksperimentov je tudi ta, da ima učitelj večjo kontrolo nad potekom eksperimenta in lahko usmerja pozornost učencev na pomembne dele eksperimenta. V raziskavi, ki je temeljila na kvantitativnem raziskovalnem pristopu, je sodelovalo 81 osnovnošolskih in srednješolskih učiteljev iz različnih statističnih regij Slovenije. Učitelji so izpolnili spletni vprašalnik, ki je vseboval štiri vsebinske sklope: (1) mnenje o učinkih izvajanja demonstracijskih eksperimentov na motiviranost učencev in uspešnost pri pouku kemije ter na kakovost učenčevega kemijskega znanja, (2) pogostost izvajanja demonstracijskih eksperimentov, (3) mnenje o demonstracijskem eksperimentu prikaza endotermne reakcije in (4) mnenje o demonstracijskem eksperimentu amonijakov vodomet. Ugotovljeno je bilo, da učitelji ne glede na delovno dobo, izobrazbo in pogostost izvajanja demonstracijskih eksperimentov po večini menijo, da demonstracijski eksperimenti pozitivno vplivajo na motiviranost in uspešnost učencev pri pouku kemije ter na kakovost učenčevega kemijskega znanja. Rezultati kažejo tudi, da večina učiteljev demonstracijske eksperimente izvaja srednje pogosto, tj. dvakrat do trikrat na mesec. Pri analizi mnenj o demonstracijskih eksperimentih prikaz endotermne reakcije in amonijakov vodomet je bilo ugotovljeno, da več učiteljev izvaja prikaz endotermne reakcije kot amonijakov vodomet. Vzroki za to so lahko nepoznavanje poskusa med učitelji, saj ni prikazan v učbenikih ne za osnovno, kot tudi ne za srednjo šolo oz. zahtevnost izvedbe eksperimenta, saj od učitelja terja malo več eksperimentalnih veščin kot eksperiment endotermne kemijske reakcije. Iz rezultatov je mogoče povzeti tudi to, da učitelji opišejo glavna opažanja pri poskusu, so pa velikokrat pri tem nenatančni in nejasni, zato je mogoče sklepati, da je lahko njihovo vodenje demonstracijskega eksperimenta tako, da podajo učencem nepopolne in lahko nebistvene informacije oz. vodijo opazovanje poskusa nenatančno. Mogoče je tudi zaključiti, da nekateri učitelji nimajo jasnega vpogleda v to, katere pojme lahko z določenim kemijskim poskusom razvijajo, kar lahko prispeva k razvoju napačnih razumevanj pri učencih ali dijakih. Chemistry is an experimental discipline which applies the experiment as one of the main research methods. Laboratory work and other practical work is also essential in chemistry education. This may be observed by the primary and secondary school curricula which are mainly based on macroscopic level activities. Practical work involves activities in which students handle substances and materials themselves or observe demonstration experiments. Demonstration experiments are typically carried out by teachers or experts who can provide the best quality demonstration to the students. The latter should participate as active learners and acquire knowledge in an experiental way. The advantage of demonstration experiments is that teachers have greater control over the whole working arrangement of the experiment and can direct students’ attention to most important parts of the experiment. Based on a quantitative research approach, 81 primary and secondary school teachers from different regions of Slovenia participated in this research study. The participating teachers filled an online questionnaire comprising four topics: (1) teachers’ perceptions on the effects of demonstration experiments on students’ motivation and performance in chemistry classes, and on the quality of the student’s chemical knowledge, (2) the frequency of performing demonstration experiments, (3) teachers’ perceptions on a demonstration experiment of endothermic reaction and (4) teachers’ perceptions on a demonstration experiment of ammonia fountain. The results show that regardless of the years of experience of teaching chemistry, teachers’ education level and frequency of performing demonstration experiments, the participating teachers perceive demonstration experiments to have a positive effect on students’ motivation and achievements in chemistry as well as on the quality of student’s chemical knowledge. The results also show that most teachers demonstrate experiments twice to three times a month. When analysing teachers’ perceptions of the two demonstration experiments (endothermic reaction and ammonia fountain), the results show that more participating teachers demonstrate the experiment of the endothermic reaction than the ammonia fountain. The reasons for this may be, that the ammonia fountain experiment is not well known among teachers because it is not included in the primary and secondary school textbooks. The other reason may be that the ammonia fountain experiment is more difficult to perform as it requires more experimental skills from the teacher than the endothermic reaction experiment. Further findings refer to the fact that the participating teachers themselves describe the main observations of the experiment. However, in doing so, they are often inaccurate and/or vague which may lead to a further assumption that the teachers’ guidance trough demonstrations may also be inaccurate. Finally, the results indicate that the participating teachers do not have a clear insight into the development of concepts that may be discerned from individual chemical experiments which may contribute to the development of misconceptions among students.