The outer elipse is an estimated 90% contour of the distribution of the least squares estimates, assuming normality. The inner ellipse is the 90% contour for the BLUPs.

Shrinkage is clearly most extreme in the nether-regions, reflecting the greater variability of these LS estimates. (These were likely subjects with few recorded visits.) The variety in the shrinkage "vectors" reflects the varying length of records and the different times at which subjects were measured.

The BLUP highlights a correlation between slope and intercept that is stronger than the "true" correlation. In general, the covariance of the BLUPs is "smaller" than that of the true population. A more technical explanation will be offered here in the future. Maybe.

The peculiar "tail" at the left end is an artifactual result of truncating repeated scores of 0. Subjects entering the study with a low score have a limited range of responses, and so have similar slopes.

These estimates can be used to provide predicted paths .