Experimentieren im Sachunterricht zwischen Wunsch und Wirklichkeit

Children like to experiment, but many teachers apparently do not. This pointedly formulated statement is supported, for example, by studies by HARLEN (1997) (1997) and MÖLLER (2004), which show that science topics – especially physical and chemical topics – as well as experimentation as a subject method are strongly underrepresented in the actual implementation of lessons in general science in primary school. Among other reasons for this underrepresentation are the teachers' lack of professional knowledge, personal reservations due to their own negative learning biography, and the lack of interest and motivation, often coupled with a low self-concept and low expectations of self-efficacy.
To address the underrepresentation, the intervention study focuses on the preparatory service in the second phase of practically based teacher training. The research question is: Can an explicit intervention on experimentation in general science in primary school using the example of bubbling gas strengthen the interest, self-concept, self-efficacy, and professional knowledge of trainee teachers in the long term?
The intervention is designed as a learning task relevant to everyday life. By thematically raising the question: "What's bubbling in the lemonade?" it explicitly includes an example from the chemical and physical domain with the subject matter carbon dioxide. From a methodological point of view, the intervention allows a constant change between practical experimentation phases and exchange and reflection phases and thus meets the demand for a hands-on as well as minds-on approach in experimental teaching.
For the longitudinal study, a mixed-methods approach is chosen for the research methodology. The intervention is investigated by means of a closed, quantitatively evaluated questionnaire for self-assessment along the characteristics of interest, self-concept, self-efficacy, and professional knowledge in a pre-post-follow-up design. After two years, the results were qualitatively validated and deepened with the help of facultative, guided interviews.
The results of the pre-post survey suggest that the intervention contributed in the short term to strengthen interest, self-concept and self-efficacy in relation to practical experimentation. The results of the follow-up survey after two years show that the typification of the individual cases into profiteers, non-profiteers and against-expectation types, which was carried out after the pre-post survey, is no longer recognisable.
For the evaluation of the interviews, it can be summarized that indirectly moderating variables such as the examined personality traits interest, self-concept, self-efficacy and professional knowledge are directly related to the strongly moderating variables such as the found school reality and that they are mutually dependent.
The intervention during the second training phase with a high level of practical relevance to primary schools is considered by the interviewed teachers to be profitable and can thus be evaluated as an important component to counteract the underrepresentation of experiments in lessons in general science in primary school.