For the positive approach, more structure leads to some alpha risk reduction even though such an improvement is unexpected because the positive approach controls for alpha risk at [absolute value of E]=0.
In general, we find that the sales behavior pattern has a significant effect on alpha risk for the negative approach and on the beta risk for both approaches for each expectation model and this influence is consistent across all expectation models.
It is apparent from the discussion earlier (table 6) that in most of the positive testing approach cases the ARIMA and Martingale models yield a significantly lower alpha risk of error detection than the structural model (table 6) and the other models (table B.
While all provide satisfactory protection against beta risk, it is apparent that both the structural and stepwise models lead to a lower level of alpha risk for the negative testing approach.
An auditor must balance the costs associated with the ease of use of these estimators against the potential costs of more audit effort due to the high alpha risk when using the negative approach.