Random coefficients models are also known as hierarchical or multilevel models (Singer 1998; Sullivan, Dukes, and Losina 1999). These models are used when batches or subjects are thought to differ randomly in intercept and slope. Drug stability trials in the pharmaceutical industry and individual growth studies in educational research often require random coefficient models.
Repeated measures designs, also known as within-subject designs, model changes in a response over time or space while allowing errors to be correlated.