Dr Aris conducted an investigation to compare the effectiveness of Acceptance and Commitment Therapy (ACT) delivered via a virtual reality (VR) headset to traditional face-to-face individual ACT sessions for managing agoraphobia. He placed posters on public noticeboards in community health centers and posted on specialized anxiety support forums online, inviting people who wished to take part to contact his research team.
Participants were assigned to one of two groups:
After eight weeks of treatment, Dr Aris assessed the change in participants' agoraphobia symptoms using a standardized self-report scale.
Explain one weakness of Dr Aris using a volunteer sampling technique in this investigation.
Practise Edexcel A Level Psychology Research methods and skills with exam-style questions for A Level Psychology. 657 questions covering Research methods and skills, matched to the Edexcel A Level Psychology (9PS0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.