Appropriate Post Hoc Comparisons for Interaction and Nested Hypotheses in Analysis of Variance Designs: The Elimination of Type IV Errors

To err is human, and now that behavioral researchers are engaging in inferential activity with increasing frequency, it is more than likely that the number of erroneous inferences is also increasing. Familiar to all seasoned hypothesis testers are those twin gremlins, Type I and Type II errors. The first faux pas refers, of course, to the rejection of a true hypothesis, while the second is the non-rejection of a false hypothesis. The rightful originator of Type III errors is disputable, as is the commonly accepted definition of them: In 1947, F. N. David, perhaps not entirely seriously, suggested that there was a third kind of error which might be committed in