Selecting the SampleSelecting the Sample

Selecting the Sample

48 The auditor shall select items for the sample with the expectation that all sampling units in the population have a chance of selection.

49 Statistical sampling requires that sample items are selected at random so that each sampling unit has a known chance of being selected. The sampling units might be physical items (such as invoices) or monetary units. With non-statistical sampling, an auditor uses professional judgement to select the items for a sample. Because the purpose of sampling is to draw conclusions about the entire population, under paragraph 48 of this Auditing Standard, the auditor needs to:

• select a representative sample by choosing sample items which have characteristics typical of the population; and
• select the sample so that bias is avoided.

50 The principal methods of selecting samples are the use of random number tables or CAATs, systematic selection and haphazard selection. Each of these methods is discussed in Appendix 3.