It is one aspect of the quality of audit evidence, the other being the relevance of evidence. Generally, the greater the risk of material misstatement of an account balance, or underlying class of transactions, the more reliable needs to be the evidence gathered. Note that when evaluating audit evidence auditors should adopt an attitude of professional scepticism . For example, evidence obtained directly from the client is considered less reliable evidence than evidence obtained directly from independent third parties. For example, evidence gathered using analytical procedures is generally considered less reliable than evidence gathered using tests of detail .
Some methods gather evidence of greater reliability than others.
For example, evidence gathered through one type of test of detail, vouching , is generally considered less reliable than evidence gathered through another type of test of detail, physical examination . This very much depends on the objective of the procedure used to gather the evidence. A more experienced or more competent auditor is less likely to make errors of judgement in gathering and evaluating audit evidence.