A researcher records the temperature of the testing laboratory in degrees Celsius, the finishing positions of participants in a cognitive speed-run task (1st, 2nd, 3rd, etc.), and the type of reward chosen by each participant ('Voucher', 'Book', or 'Snack').
Which of the following statements regarding these levels of measurement is correct?
The finishing positions (1st, 2nd, 3rd, etc.) represent interval data because the numerical difference between consecutive ranks is consistently one unit.
The categories of reward ('Voucher', 'Book', 'Snack') represent nominal data, which provides the highest level of measurement precision and allows for the calculation of a standard deviation.
The laboratory temperature is interval level data, which offers a higher level of precision than the finishing positions and permits the calculation of a mean.
Converting the continuous laboratory temperatures into discrete categories of 'Cold' (<18∘C< 18^\circ\text{C}<18∘C) and 'Warm' (≥18∘C\ge 18^\circ\text{C}≥18∘C) upgrades the data from interval to nominal level.
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.