Guided Notes

Correlation & Regression Basics

Scatter plots, correlation coefficients, simple and multiple regression, logistic regression for yes/no outcomes, and why correlation is not causation in healthcare data.

Relationships between variables

Slide 1 / 5

Questions like 'Do older patients stay longer?' or 'Does staffing relate to falls?' are about relationships. • Start with a scatter plot. • Correlation (r, from −1 to +1) measures the strength and direction of a LINEAR relationship. • r ≈ 0.1 weak, 0.3 moderate, 0.5+ strong (rough guide). • Outliers and non-linear patterns can fool r — always look at the plot.