OrgWASTE: Using citizen science to educate people about the decomposition of organic matter and promote sustainable waste management practices

Abstract

The OrgWASTE Citizen Science (CS) project is predicated on the implementation of a Teaching-Learning Sequence (TLS) with a socio-constructivist orientation and based on conceptual change theory. The design of the TLS was informed by an analysis of students' conceptions and took into account the existing teaching limitations on urban waste decomposition in secondary education. During the 2024/2025 academic year, a series of activities were conducted in six secondary schools in the city of Seville (Spain) with the objective of enhancing comprehension of decomposition processes and nutrient cycles, while concurrently promoting sustainable practices in organic waste management. The intervention incorporated scientific content into practical inquiry experiences, specialised talks and scientific outreach activities. The evaluation of this SEA was based on a pre-post design with ad hoc questionnaires, with 114 responses recorded in the pre-test phase and 91 in the post-test phase, from students in the 3rd and 4th years of compulsory secondary education (ESO). The responses were analysed using a qualitative approach (phenomenography) to explore progress in the students' mental models and quantitatively using statistical analysis. Phenomenographic analysis (κ = 0.92) revealed a significant improvement in understanding what the products of decomposition are (compost, nutrients, soil). Greater willingness and progress in waste separation were also observed. It is concluded that CC-based SEA, such as that implemented in OrgWASTE in secondary school students, are effective tools for integrating scientific content with participatory actions, promoting contextualised and meaningful learning, and improving commitment to sustainability.