Multivariate Data and Scatterplots

Question 1

What is homoscedasticity?

Answer 1

When the scatter in Y is about the same in different vertical slices through a scatterplot, the data (and the scatterplot) are said to be homoscedastic (equal scatter).

In other words there is no variance in the variance.

Question 2

What is heteroscedasticity?

Answer 2

When the scatter in Y is not the same in different vertical slices through a scatterplot, the data (and the scatterplot) are said to be heteroscedastic (unequal scatter).

In other words there is variance in the variance.