## 1.2 Descriptive studies

Descriptive studies are used to answer descriptive RQs (Fig. 1.1).

Definition 1.1 (Descriptive study) In a descriptive study, researchers only focus on collecting, measuring, assessing or describing an outcome in the population.

Example 1.2 (Descriptive study) Consider this RQ:

For overweight men over 60, what is the average increase in heart rate after walking 400 metres?

The outcome is the average increase in heart rate. The response variable is the increase in heart rate for the individual men.

The increase in heart rate would need to be found by measuring each man's heart rate before the walk, then their heart rate after the walk, and finding the difference between them. The increase in heart rate would be computed as the after heart rate minus the before heart rate.

Some of these differences might be positive numbers (heart rate went up), and some may be negative numbers (heart rate went down).

No comparison being made: every man in the study is treated in the same way. This is a descriptive RQ, which can be answered by a descriptive study.