The test data approach involves testing the controls by: - entering test transactions that should be accepted (no errors) and seeing that they are processed correctly. - entering test transactions that should be rejected (errors) and seeing that they are rejected for the right reasons. - the auditor's predetermined results are compared to actual results from the system - tests can not be conducted directly on the client's master files to avoid contaminating the clients' records The next test is Integrated test facility (ITF). It is similar to the test date technique except that the test processing occurs using the client's 'live' files. as such testing can occur without the client personnel knowing (i.e., continuous check/ processing of auditor's data) For example, the auditor may: + add a 'dummy' customer record to the client's system + process real transactions against it to check they are processed correctly Other tests: Parallel simulation: reprocessing the client's actual data on the auditor's system and comparing the results to the original results. Program code review: involves reviewing relevant software code line by line, considering whether processing steps and control procedures are properly coded and logically correct.