Question

When would it be appropriate to use a priori contrasts, or one of the a posteriori procedures? Briefly justify your choice.

Answer 1

Solution:

Priori contrast are the planned comparisons and posteriori procedures are unplanned comparisons to isolate differences among means in the analysis of variance research. Planned or priori comparisons are typically involve weighting data by sets of contrasts. Planned comprison or priori contrasts provide more power against TYPEII errors. Priori research force the researcher to be more thoughtful in conducting research.

These are the two reasons which makes planned or priori comparisons Superior to the unplanned comparisons.