Marcus is interested in finding out if there is a relationship between daily smartphone screen-time and levels of anxiety. To investigate this, he pins flyers on noticeboards around a local fitness center, asking for volunteers to scan a QR code to complete an online survey. Fifteen participants completed his survey, providing self-report data on their average daily screen-time (in hours) and their anxiety levels rated on a scale of 0 to 50.
Explain one strength and one weakness of using this sampling method for Marcus's 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.