Nature of Computers
Three broad classes of application controls
Designed to ensure that the transactions that bring data into the system are valid, accurate, and complete
Input controls
Data input procedures can be:
Classes of input controls:
Five CAATTs approaches used for testing application logic:
Source document input requires human involvement and is prone to clerical errors.
True
Direct input employs real-time editing techniques to identify and correct errors immediately.
True
Controls in systems that are using physical source documents.
Source document controls
Control procedures over source documents:
Checks on the integrity of data codes used in processing.
Data Coding Controls
Three types of processing errors:
Three classes of transcription errors:
Occurs when an extra digit or character is added to the code.
Addition errors
Occurs when a digit or character is removed from the end of a code.
Truncation errors
The replacement of one digit in a code with another.
Substitution errors
Occurs when two adjacent digits are reversed.
Single transposition errors
Occurs when non-adjacent digits are transposed.
Multiple transposition errors
Data coding controls:
Check digits
A control digit added to the code when it is originally assigned that allows the integrity of the code to be established during subsequent processing. (suffix, prefix, embedded)
Check digits
Check-digit techniques:
The steps in modulus 11:
An effective method of managing high volumes of transaction data through a system, especially paper-fed information system.
Batch controls
Batch controls provide assurance that: