Coach Sterling wants to investigate the impact of a daily 15-minute mental rehearsal routine on the free-throw percentage of local basketball players. He sends an email to all registered players in the regional league inviting them to contact him if they would like to participate in the research.
Identify the sampling technique used by Coach Sterling in this study.
638 exam-style questions on Edexcel A Level Psychology Methods. Each one has a worked solution and a mark scheme showing where the marks go.