7.4: Statistical tests

Question 1

Researchers were interested in the spatial awareness skills of motorists. They decided to investigate a possible relationship between different aspects of spatial awareness. Motorists who had between ten and twelve years of driving experience and held a clean driving licence with no penalty points were asked to complete two sets of tasks.

Set 1: To follow a series of instructions and using a map, to identify various locations correctly. This provided a map reading score for each motorist with a maximum score of 20.

Set 2: To complete a series of practical driving tasks accurately. This involved tasks such as driving between cones, driving within lines and parking inside designated spaces. Each motorist was observed completing the Set 2 tasks by a single trained observer who rated each performance by giving the driver a rating out of 10.

The researchers decided to analyse the data using a Spearman’s rho test. Explain why this is a suitable choice of test for this investigation (3 marks)

Answer 1

This is a suitable choice of test for this investigation, because:

1. The test determines the strength of a relationship between two variables which is what the researchers were looking for in their initial aim
2. The data is in related pairs
3. The variables under test are both ratings measured at the ordinal level