A. Edit programs or input validation routines are programs that check the validity and accuracy of input data. They perform edit tests by examining specific fields of data and rejecting transactions if their data fields do not meet data quality standards. Edit tests include completeness checks, which ensure that data is input into all required fields; limit checks, which ensure that only data within predefined limits will be accepted by the system; validity checks, which match the input data to an acceptable set of values or match the characteristics of input data to an acceptable set of characteristics; overflow checks, which make sure that the number of digits entered in a field is not greater than the capacity of the field; key verification, or the process of inputting the information again and comparing the two results; and check digits, which can be used for determining whether a number has been transcribed properly. A check digit is a digit that is a function of the other digits within a set of numbers. If a typographical error is made in input, the check digit will recognize that something has been input incorrectly.
B. A compiler translates programs written in a higher level language into machine language. Computer programs are error tested by using a compiler, which checks for programming language errors. However, a compiler does not check the validity or accuracy of transaction data during input.
C. An Integrated Test Facility (ITF) involves the use of test data and the creation of fictitious entities, such as fictitious employees, fictitious vendors, fictitious products, and fictitious accounts, within the master files of the computer system. Or alternatively, a separate, fictitious company may be used. The test data in an ITF are processed along with real data. No one knows that the data being processed includes these fictitiousentries to fictitious records. An Integrated Test Facility is used by an auditor to check the operation of programs. By checking them this way, the auditor can be sure that the programs being checked are the same programs as those that are being used to process the real data. However, an Integrated Test Facility does not check the validity or accuracy of transaction data during input.
D. The operating system controls the operation of the system but it does not check the validity or accuracy of transaction data during input.
