THE TREATMENTS

Subjects will receive different treatments. That is what the experiment is investigating. Often, the treatment can be considered as affecting the subject for the duration of the experiment. If the treatment is varied within the subjects (i.e. a cross-over trial), then different sequences can be considered as different treatments, and the treatment effect is partly assessed by examining the time effect.

If all treatment sequences are to be compared, then these may be randomised among subjects (e.g. by a latin square) and the design considered as standard, and a repeated measures approach is not needed (although some allowance for carryover effects may be required).

A combined approach is needed when all sequences are considered, but each subject is measured a number of times on each treatment.

Antedependence Modelling 27.2.96