Explain why in most instances audit evidence is persuasive rather than convincing

Audit evidence is usually persuasive rather than convincing for two reasons. First, since an audit must be completed in a reasonable amount of time and at a reasonable cost, the auditor examines only a sample of the transactions that compose the class of transactions or account balance. Second, due to the nature of evidence, auditors must often rely on evidence that is not perfectly reliable. The types of audit evidence examined by the auditor have different degrees of reliability, and even highly reliable evidence has weaknesses. Therefore, the evidence obtained by the auditor seldom provides absolutely convincing evidence about an audit objective.