What does a correlation coefficient measure?

A correlation coefficient measures the strength and direction of a relationship between two variables. It quantifies how closely the two variables are related, providing a numeric value that ranges between -1 and +1. A coefficient close to +1 indicates a strong positive relationship, meaning that as one variable increases, the other one tends to increase as well. Conversely, a coefficient close to -1 indicates a strong negative relationship, showing that as one variable increases, the other tends to decrease. A correlation coefficient of 0 suggests no relationship between the variables.

This concept is critical in research and data analysis, especially in fields like maternal-fetal medicine, where understanding the relationships between maternal health indicators and fetal outcomes can help in decision-making and predicting complications. Being able to assess how strongly two variables are associated gives clinicians and researchers insight into potential areas for further investigation or intervention.