A researcher investigates the effect of ambient room temperature (either 16∘C16^\circ\text{C}16∘C or 26∘C26^\circ\text{C}26∘C) on participants' cognitive performance. All participants in the 16∘C16^\circ\text{C}16∘C condition are tested in the morning, whereas all participants in the 26∘C26^\circ\text{C}26∘C condition are tested in the late afternoon.
In this experimental design, what is the status of the 'time of day' variable?
It is the independent variable because the researcher deliberately alters it to measure its effect on cognitive performance.
It is a confounding variable because it systematically varies alongside the independent variable, making it impossible to isolate the true cause of any change in cognitive performance.
It is the dependent variable because the time at which testing occurs is measured and recorded for each participant.
It is an extraneous variable that has been successfully controlled through standardisation to ensure the internal validity of the study.
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.