Sample Size Calculation

The concept behind the calculation of sample sizes is where the size of the sample, or the risk level associated with a test, will vary depending on the audit area/assertion combinations that the test provides audit evidence for. For both standard and pool tests, the system calculates sample sizes and risk factors as follows:

• On selecting a test, the system sets the sample size or interval based on the highest risk/reliance associated with any assertions that the test has been linked to. (Maximum sample sizes  can be specified for the stratification calculation, in the sample size table.)

• On signing off planning, the system reviews all tests that have been selected and, provided the planner has not overridden the sample size, resets the sample size to the highest risk/reliance associated with any assertions to which the test has been selected to provide audit evidence.

• When calling the stratification calculator, the system calculates the risk level based on the actual assertions against which the test has been linked.

• On a balance forward, all sample sizes and stratification calculations are cleared.

In the case of standard tests, in addition to the assertions to which the test has been linked, the tests are considered linked to all assertions that are shown in the assertion column for the test.

If a stratified sample has been calculated and the risk subsequently changed, the system asks if you wish to recalculate the sample if you then access the calculator again for the test. If you do, and planning has been signed off, details are appended to the comments box of the change made.