A retail psychologist investigates whether background music tempo influences the walking speed of shoppers. On alternating days over two weeks, they play either fast-tempo or slow-tempo instrumental music in a large department store and record the time it takes customers to walk down a designated aisle.
Which of the following is a methodological weakness of this research design?
The highly artificial setting and task increase the risk of demand characteristics.
The researcher is unable to manipulate the independent variable, preventing a cause-and-effect relationship from being established.
Extraneous environmental variables are difficult to control, which may threaten internal validity.
Random allocation of participants is mandatory, which increases the likelihood of selection bias.
644 exam-style questions on OCR A Level Psychology Research methods and techniques. Each one has a worked solution and a mark scheme showing where the marks go.