Testing the assumption of Normality and Homoscedasticity
A quantile-quantile graph was plotted in R- software for the best-fitted model and visually verified that almost the cluster of points forms a straight line. Homoscedasticity characterized by a constant variance of the residuals was also checked by plotting the residuals against the fitted values in R software and visually verified that more or less the cluster of points does not show any particular trend (Figure 3).
Figure 3. Residuals plotted against fitted values (upper-left), quantile–quantile plot (lower left), scale-location plot (upper - right) and plots for each point leverage (lower-right)for best fitted model of Pouteriaadolfi-friederici