Dr. Vance conducted an investigation to determine whether inhaling rosemary essential oil improves cognitive alertness compared to a control condition with no scent. She matched participants on their initial cognitive processing speed to form pairs; one member of each pair completed an alertness task in a room scented with rosemary, while the other completed it in an unscented room. The level of alertness was measured using a 10-point subjective rating scale, yielding ordinal data.
Identify three reasons why Dr. Vance should use the Wilcoxon signed-ranks test to analyse her data.
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.