Clean waste streams are crucial for material valorisation, which remains a challenge shaped by citizens’ daily practices. This study examines waste-sorting behaviour in a university office and assesses the impact of a co-created Campus Living Lab (CLL) experiment designed to improve it. The intervention, “Sort-it-out", was gamified and co-created with campusians (the campus's citizens). Observed sorting behaviour was assessed via waste scans, and the results were explained by conducting a survey. The survey was grounded in the Theory of Planned Behaviour (TPB), and had a sorting task, from which we derived waste sorting performance (WSP), a new dependent variable. It was analysed using three dependent variables and two regression models: WSP, waste sorting intention (WSI), and waste sorting behaviour (WSB). Results of the waste scans showed consistently high correct disposal for organic and paper streams, moderate improvements for plastics and drink cartons (PD), and minor declines in general waste sorting. Regression results indicated that WSI was primarily explained by attitude (ATT), and that WSB was explained by ATT and perceived behavioural control (PBC). However, TPB constructs had limited predictive power for WSP, suggesting that other factors, such as professional background, may influence it. The findings highlight the value of co-created, context-specific interventions to raise awareness and the importance of knowledge in waste sorting behaviours.
Stuckrath et al. (Fri,) studied this question.