A free online lecture
Understand that when a disease measure is under homeostatic control, animals presented for treatment when clinical signs are near their worst will expectedly improve in subsequent time periods. even if the treatment is totally infeffectual.
Understand that rates of disease in a population can also be subject to regression to the mean. Treatments given when disease rates are near their worst may subsequently drop due to regression to the mean, giving the false impression that the treatment was effective.
Understand that regression to the mean would be likely to occur following a randomly selected time point.
Understand that regression to the mean would not be expected to occur when a disease has not yet reached a homeaostatic "steady state" in eiter an individual or a population.
Link to the lecture: http://amrls.cvm.msu.edu/amr/rtm/