AIS Chapter 10 Terms

Hash Total

A type of batch total generated by summing values for a field that would not usually be totaled. (e.g., employee number, number of hours)

Record Count

A type of batch total that equals the number of records processed at a given time.

Differential Backup

A type of partial backup that involves copying all changes made since the last full backup. Thus, each new differential backup file contains the cumulative effects of all activity since the last full backup.

Validity Check

An edit test that compares the ID code or account number in transaction data with similar data in the master file to verify that the account exists.

Transposition Error

An error that results when numbers in two adjacent columns are inadvertently changed (for example, 64 is written as 46). If is evenly divisible by 9 then you can calculate if it is a transposition error.

Parity Bit

An extra bit added to every character; used to check transmission accuracy.

Closed-loop Verification

An input validation method that uses data entered into the system to retrieve and display other related information so that the data entry person can verify the accuracy of the input data.

Financial Total

A type of batch that equals the sum of a field that contains monetary values.

Backup

A copy of a database, file, or software program.

Archive

A copy of a database, master file, or software that is retained indefinitely as a historical record, usually to satisfy legal and regulatory requirements.

Parity Checking

A data transmission control in which the receiving device recalculates the parity bit to verify accuracy of transmitted data.

Checksum

A data transmission control that uses a hash of a file to verify accuracy.

Cold Site

A disaster recovery option that relies on access to an alternative facility that is prewired for necessary telephone and Internet access, but does not contain any computing equipment.

Hot Site

A disaster recovery option that relies on access to an completely operational alternative data center that is not only prewired but also contains all necessary hardware and software.

Redundant Arrays of Independent Drives (RAID)

A fault tolerance technique that records data on multiple disk drives instead of just one to reduce the risk of data loss.

Business Continuity Plan (BCP)

A plan that specifies how to resume not only IT operations but all business processes in the event of a major calamity.

Disaster Recovery Plan (DRP)

A plan to restore an organization's IT capability in the event that its data center is destroyed.

Zero-balance Test

A processing control that verifies that the balance of a control account equals zero after all entries to it have been made.

Cross-footing Balance Test

A processing control which verifies accuracy by comparing two alternative ways of calculating the same total.

Turnaround Document

A record of company data sent to an external party and then returned by the external party for subsequent input to the system.

Incremental Backup

A type of partial backup that involves copying only the data items that have changed since the last partial backup. This procedure a set of incremental backup files, each containing the results of one day's transactions.

Sign Check

An edit check that verifies that the data in a field have the appropriate arithmetic sign. (-,+)

Uninterruptible Power Supply (UPS)

An alternative power supply device that protects against the loss of power and fluctuations in the power level by using battery power to enable the system to operate long enough to back up critical data and safely shut down.

Reasonableness Test

An edit check of the logical correctness of relationships among data items. (e.g., overtime hours should be zero for someone who has not worked the maximum number of hours)

Sequence Check

An edit check that determines if a batch of input data is in the proper numerical or alphabetical sequence.

Size Check

An edit check that ensures the input data will fit into the assigned field. (e.g., 458,976,253 will not fit in an eight digit field).

Limit Check

An edit check that tests a numerical amount against a fixed value.

Range Check

An edit check that tests whether a data item falls within predetermined upper and lower limits.

Field Check

An edit check that tests whether the characters in a field are of the correct field type (e.g., numeric data in numeric fields).

Completeness Check (or test)

An edit check that verifies that all data required have been entered.

Prompting

An online data entry completeness check that requests each required item of input data and then waits for an acceptable response before requesting the next required item.

Concurrent Update Controls

Controls that lock out users to protect individual records from errors that could occur if multiple users attempted to update the same record simultaneously.

Full Backup

Exact copy of an entire database.

Check Digit

ID numbers (such as employee number) can contain a check digit computed from the other digits.

Real-time Mirroring

Maintaining complete copies of a database at two separate data centers and updating both copies in real-time as each transaction occurs.

Check Digit Verification

Recalculating a check digit to verify that a data entry error has not been made.

Recovery Point Objective (RPO)

The amount of data the organization is willing to reenter or potentially lose.

Fault Tolerance

The capability of a system to continue performing when there is a hardware failure.

Recovery Time Objective (RTO)

The maximum tolerable time to restore an organization's information system following a disaster, representing the length of time that the organization is willing to attempt to function without its information system.

Batch Totals

The sum of a numerical item for a batch of documents, calculated prior to processing the batch, when the data are entered, and subsequently compared with computer-generated totals after each processing step to verify that the data was processed correctly.

Header Record

Type of internal label that appears at the beginning of each file and contains the file name, expiration date, and other file identification information.

Trailer Record

Type of internal label that appears at the end of a file; in transaction files, the trailer record contains the batch totals calculated during input.