Confidence levels in sampling include the options for a level from 0.5 to 2.0. Selecting over 1.0 creates a larger sample in situations in populations where risk is judged as higher.
In cases where because of the auditor's confidence in system controls fewer items are required to be tested substantively a factor lower than 1.0 may be selected. If for instance a factor of 0.5 is selected the number of items required will be reduced as follows:
See detailed article on risk assessment and sampling.