Marcus investigated whether 18-month-old infants learn new vocabulary faster when hearing words spoken by a high-pitched virtual assistant compared to a low-pitched virtual assistant. To recruit his participants, he placed an advertisement in a popular weekly parenting magazine, requesting parents of 18-month-old infants to contact him if they wished to participate.
Marcus asked the parents in Group A to play a 5-minute recording of the high-pitched assistant naming common household objects daily for a week, while parents in Group B played the same recording but with the low-pitched assistant. He then measured the infants' word recognition using a gaze-tracking task in his laboratory.
Explain one weakness of Marcus using a volunteer sampling technique for his 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.
