Dot Chart

The Dot (Marker) Chart displays values of two variables in the form of dots in the Cartesian coordinate system. It is used to show the presence or absence of a relationship between two variables. Markers corresponding to different types of phenomena can be depicted with different colors.

A measure of the relationship between two variables is called a correlation.
If it is possible to draw a nearly straight line between markers on a dot diagram, the correlation between these variables is high. If markers are distributed evenly, then the correlation is low or even equals zero.