Figure 1.
Figure 1.

Illustrative demonstration of heterogeneity of variances and of mean performance in ADG between hypothetical groups of feedlot cattle. Depicted is the distribution of ADG for 3 hypothetical groups of cattle, representative of 3 levels of a fixed effect factor (i.e., managerial practices or demographic factors). The comparison of Group 1 and Group 2 shows a situation where groups have different mean performance but similar variability around their means (i.e., homogeneous variances). In contrast, Group 1 and Group 3 share the same mean, yet Group 3 has greater dispersion around that mean than Group 1 (i.e., heteroskedasticity or heterogeneity of variances).