Auditoria

TYPES OF CORROBORATING INFORMATION
As noted previously, evidential matter consists of underlying accounting data and corroborating information. The auditing student should already be familiar with the basic components of underlying accounting data identified in journals, ledgers, worksheets, reconciliations, etc. in this section; we identify and elaborate upon eight principal types corroboratinginformation as follows:
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* Analytical evidence
* Documentary evidence
* Confirmations
* Written representations
* Mathematical evidence
* Oral evidence
* Physical evidence
* Electronic evidence

For each type, consideration is given to its nature, reliability, and the categories of assertions to which it is most relevant. Selected observations are alsomade regarding relative cost and frequency of use.
ANALYTICAL EVIDENCE.
Analytical evidence involves comparisons of current-period client data, such as total revenues or return on assets, with expected values for the data based on historical or budgeted amounts for the client or industry data. The comparisons are the used to draw inferences about the fairness of financial statements assertions.The reliability of analytical evidence is dependent on the relevance of the comparable data. For example, if there have been no significant changes in the nature and size of client´s operations, customer base, and other factors from the previous year of several years, a comparisons of the historical pattern of monthly sale with the monthly sale data for the current period should provide reliableanalytical evidence about the fairness of total revenues reported for the current period.
When several related financial variables all conform to expectations, the reliability of the analytical evidence may be further enhanced.
DOCUMENTARY EVIDENCE
Documentary evidence includes a wide variety of source documents as well as such items as minutes of board of director or executive committeemeetings, lease agreements, various other contracts, and bank statements. Ordinarily, these documents, which may be generated externally or internally, are contained in client files and are available for the auditor´s inspection upon request.
Examples of externally generated documents include customer order forms, suppliers´ invoices, tax bills, and bank statements. Externally generated documents aregenerally considered to be more reliable than internally generated documents. The reliability of externally generated documents is further enhanced when they are sent directly from the external party to the auditor, thus eliminating the opportunity for the client to alter the documents before the auditor sees them.
Examples of internally generated documents include sale order forms, shippingdocuments, sales invoices, purchase requisitions, purchase orders, receiving reports, time cards, and paid (canceled) checks. Since it is possible for internal documents to be created by client employees merely to support journal entries for fictitious transactions, the reliability of internally generated documents is enhanced when they bear evidence of having been circulated to external parties beforebeing placed in the client´s files.
The physical characteristics of documents may also affect their reliability. For example, the use of special papers and links, prenumbering, and machine-imprinted data are all designed to make it more difficult to alter documents or to create phony documentation.
CONFIRMATIONS
Confirmations constitute a special class of documentary evidence involving directwritten responses by knowledgeable third parties to specific request for factual information. The following are illustrative of items that are frequently confirmed:
Item | Knowledgeable respondent |
Cash in bank | Bank |
Accounts receivable | Individual customers |
Inventory stored in public warehouse | Warehouse custodian |
Inventory out on consignment | Consignee |
Accounts, notes,...