## 2.5 Relationships between two Numerical Variables

### Guidelines to Analysing Numerical Associations

- Begin with context: what does the data represent?
- Identify the explanatory and response variables.
- Assess the form of the association: is it
**linear, non-linear**or is there**no association**. - If it is linear, assess the strength (
**strong, moderate or weak**). Ideally, do this using the Pearson’s correlation coefficient (detailed in 2.6 Pearson’s Correlation Coefficient), however if the raw data is not available, a qualitative assessment will suffice.