A local council is conducting a multi-year study to investigate the effectiveness of a new household recycling campaign. They obtain a sample of 200 households by asking for volunteers via a post on a local social media group dedicated to 'Zero-Waste Living'.
Briefly explain one limitation of using this self-selected (volunteer) sample for this study.
689 exam-style questions on AQA A Level Psychology Scientific processes. Each one has a worked solution and a mark scheme showing where the marks go.