AUD Sampling Questions Keep Asking “Increase or Decrease.” How Do You Solve Them?
Sampling becomes much easier when you ask one question: did the auditor just demand stronger evidence?
Risk of assessing control risk too low
If the auditor wants less risk of incorrectly relying on a control, the auditor needs stronger evidence. Stronger evidence generally means a larger sample.
Tolerable deviation rate
If the auditor becomes less tolerant of control deviations, the sample generally increases. If the auditor is willing to tolerate more deviation, the sample can generally decrease.
Expected deviation rate
If more deviations are expected in the population, the auditor generally needs a larger sample to evaluate it effectively.
Variables sampling
Use the same logic for substantive sampling. Lower tolerable misstatement generally increases sample size. Higher expected misstatement generally increases sample size.
Do not overfocus on population size
Candidates often assume that a larger population always creates a proportionally larger sample. Sampling does not always behave that simply, especially once populations are already large.
Build direction cards
Acceptable risk down → sample up
Tolerable error down → sample up
Expected error up → sample up
Then explain why each relationship exists.
The takeaway
When the auditor demands more confidence or tolerates less error, expect more audit work.
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FAQ
If tolerable deviation increases, what happens to sample size?
Sample size generally decreases because the auditor is willing to tolerate more deviation.
If expected deviation increases?
Sample size generally increases.
Do I need every sampling formula memorized?
Know the concepts and formulas your current materials require, but directional reasoning can solve many questions.