Tolerable and Expected Definitions
11. When using a statistical sample, the auditor should consider concepts such as
sampling risk and tolerable and expected errors. Sampling risk arises from the possibility
that the auditor’s conclusion may be different from the conclusion that would be reached if
the entire population were subjected to the same audit procedure. There are two types of
sampling risk:
— the risk that the attribute or assertion tested is assessed as
unlikely when, in fact, it is likely.
ection — the risk that the attribute or assertion tested is assessed as likely
when, in fact, it is not likely.
Tolerable errors are the maximum numbers of errors that the auditor is willing to accept
and still reach a conclusion that the underlying assertion is correct. This is not always the
auditor’s decision and may be determined by the nature of the business, consultation with
management or best practices. In some cases, an error of one will not be tolerable.
Expected errors are errors that the auditor expects in the population based on prior audit
results, changes in processes, and evidence/conclusions from other sources.
12. The level of sampling risk that the auditor is willing to accept, tolerable error, and the
expected error all affect sample size. Sampling risk should be considered in relation to the
audit risk approach and its components which include inherent risk, control risk, and
detection risk.
13. Effective audit sampling procedures will increase the coverage, focus, and efficiency
of audits and will allow the auditor to provide assurance on business processes that
impact the organization’s achievement of its goals and objectives. It is important that the
auditor understand accepted guidance and standards on sampling along with the
business processes and data he or she is working with when selecting the appropriate
audit sampling technique.