Glossary term

Scatter Diagram: Meaning and Definition

Reviewed and approved by Dr. Anamika ShrivastavaPublished Last updated

A scatter diagram plots each pair of values of two variables as a point on a graph. The pattern of the points shows whether the relationship is positive, negative or absent, and how close it is to a straight line. It is drawn before calculating a correlation coefficient.

In more detail

A scatter diagram is the first step in studying two variables. It shows direction, strength and any outliers, and warns when a relationship is curved rather than straight. A line fitted through the points summarises the trend and can be used for rough prediction within the range of the data.

Example

Plotting weekly study hours on the horizontal axis and marks on the vertical axis for six students gives points that rise from left to right, showing positive correlation.

Key points

  • Rising pattern: positive correlation.
  • Falling pattern: negative correlation.
  • Shapeless cloud: no correlation.

Common mistake

Using a scatter plot to claim cause. It shows association only.

Correlation

Where it is explained

This term is explained in Class 11 Statistics Chapter 6: Correlation.