# Interpreting a Q-Q Plot Correctly

I have the following Q-Q plot that was generated from an Two-Way ANOVA in R. Here is the ANOVA: And here is the Q-Q plot: I've generated a Q-Q plot of the ANOVA residuals. Are the following statements correct?

1) The residuals follow a roughly normal distribution (which is what we want) since the Q-Q line is mostly a straight line.
2) The x-axis represents standard deviations from the mean of the residuals
3) The y-axis represents the range of residuals. Roughly -.4 to .6


## 1 Answer

1) yes, in a perfect case, the qqplot will show dots following a straight 45 degree line.

2) the X-axis shows the theoretical values of the quantiles of the standard normal distribution.

3) the y axis shows the empirical values of the quantiles of your data set

each point of the plot is a data point with coordinates that correspond to the empirical quantile and theoretical quantile of that data point. if these quantiles match, then the point will lay in the 45 degree line.