The auditor should consider following while evaluating audit evidence:
i. Sufficiency of evidence
There is no hard and fast rule concerning the precise amount of evidence that the auditor must collect for each audit area. The auditor uses his own skill and judgment to decide how many items
to test, for example, in his main sales test. The knowledge of the business, the degree of risk associated with the test, and the reliability of the evidence collected will assist in the decision. For each client, however, the decision must be made. The consideration here, then is that each client is different, and that no standard testing quantity can be applied to all clients‟ the auditor must always use his own skill and judgment to decide the appropriate testing level.
ii. Relevance of audit evidence
The evidence collected should not be use dot draw conclusions about testing objectives not in fact covered that test. Thus, merely because a fixed asset register correctly adds up does not mean that all the individual assets actually exist, or that they are correctly valued. The auditor must always ensure that the correct tests are used for the audit objective under consideration.
iii. Degree of Knowledge
In some situations, the auditor may have the evidence available to him but he may not be able to evaluate this properly. For example, at a jewelry store he may not be able to value the stock correctly. In this case special advice should be sought. Similarly, the auditor may not understand the evidence as in the case of some legal contracts, and here a solicitor may be needed to explain fully the effect of the contract on the client.