Attribute Sampling
For tests of controls. Based on Poisson reliability factors from AICPA Audit Sampling Guide.
Complement of risk of overreliance (e.g. 95% = 5% risk).
5%
Max rate of deviation you can accept and still rely on the control.
1%
Rate you expect based on prior audits.
Used for finite population correction when sample exceeds 10%.
Recommended sample
75
items to test
Unadjusted: 75
Formula: n = RF / (TDR − EDR), where RF is the reliability factor at 95% confidence.