Information_Technology 1 Flashcards
Input controls - objective
Overall controls
(a) Inputs should be properly authorized and approved.
(b) The system should verify all signifi cant data fi elds used to record information (editing the data).
(c) Conversion of data into machine-readable form should be controlled and verifi ed for accuracy.
Batch total
Batch total is an input control, the sum of the number of items or total amount. Input is compared to processing; a mismatch of the number of items or sum of the totals (e.g., sum of invoice totals) between input and processing indicates that an item was lost or processed twice.
Source Data Controls
Source Data Controls
The following controls make sure source documents and other input data are authorized, accurate, complete, accounted for properly, entered into the system, and sent to their intended destination in a timely manner. They should also make sure the data has not been suppressed, duplicated, or otherwise improperly changed.
a. Design source documents such that they minimize errors and omissions.
b. Prenumber all documents and have the system identify and report any missing or duplicate numbers.
c. Restrict source document preparation to authorized personnel.
d. Require all source documents, where required, to be properly authorized before processing them.
e. Use machine-readable turnaround documents (company data sent to an external party and returned to the system as input) to reduce data input time, effort, expense, and errors.
f. Cancel documents that have been entered into the system so they cannot be reused.
(1) Deface paper documents by marking them paid or perforating them.
(2) Flag electronic documents to show they have been canceled.
g. Retain original source documents long enough to satisfy legal requirements.
h. Use check digit verification.
(1) ID numbers can have a check digit computed from the other digits. For example, a six-digit account number can have a seventh digit, which is the check digit.
(2) Data entry devices verify the check digit each time the ID number is entered by using the six digits to recalculate the seventh check digit.
(3) The verification calculation will not match the check digit if an error is made in entering the six digits or the check digit.
i. Use key verification.
(1) An employee rekeys data entered through a keyboard.
(2) The system compares the two sets of keystrokes.
(3) Discrepancies are highlighted for correction.
(4) Key verification is used for crucial input such as customer numbers and amounts.
Type Input validation (edit) controls
(a) Preprinted form— Information is preassigned a place and a format on the input form.
(b) Check digit— An extra digit added to an identifi cation number to detect certain types of data transmission errors. For example, a bank may add a check digit to individuals’ 7-digit account numbers. The computer will calculate the correct check digit based on performing predetermined mathematical operations on the 7-digit account number and will then compare it to the check digit.
(c) Control, batch, or proof total — A total of one numerical fi eld for all the records of a batch that
normally would be added, (e.g., total sales dollars).
(d) Hash total— A control total where the total is meaningless for fi nancial purposes (e.g., a
mathematical sum of employee social security numbers).
(e) Record count— A control total of the total records processed.
(f) Limit (reasonableness) test— A test of the reasonableness of a fi eld of data, given a predetermined
upper and/or lower limit (e.g., for a fi eld that indicates auditing exam scores, a limit check would
test for scores over 100).
(g) Menu driven input— As input is entered, the operator responds to a menu prompting the proper
response (e.g., What score did you get on the Auditing part of the CPA Exam [75-100]?).
(h) Field check— A control that limits the types of characters accepted into a specifi c data fi eld (e.g., a
pay rate should include only numerical data).
(i) Validity check— A control that allows only “valid” transactions or data to be entered into the
system (e.g., a fi eld indicating sex of an individual where 1=female and 2=male—if the fi eld is
coded in any other manner it would not be accepted).
(j) Missing data check— A control that searches for blanks inappropriately existing in input data (e.g.,
if an employee’s division number were left blank an error message would result).
(k) Field size check— A control of an exact number of characters to be input (e.g., if part numbers all
have 6 digits, an error message would result if more or less than 6 characters were input).
(l) Logic check— Ensures that illogical combinations of input are not accepted (e.g., if the Tuba City
branch has no company offi cers, an error message would result if two fi elds for a specifi ed
employee indicated that the employee worked as an offi cer in Tuba City).
(m) Redundant data check— Uses two identifi ers in each transaction record (e.g., customer account
number and the fi rst fi ve letters of customer’s name) to confi rm that the correct master fi le record is
being updated.
(n) Closed-loop verifi cation— A control that allows data entry personnel to check the accuracy of input
data. For example, the system might retrieve an account name of a record that is being updated, and
display it on the operator’s terminal. This control may be used instead of a redundant data check
Database Management System (DBMS)
- A DBMS (database management system) consists of computer program(s) for organizing, accessing, and modifying a database. It is a collection of programs that enables users to store, modify, or extract information from a database.
- The primary purpose of a database management system is to reduce data redundancy.
Distributed data processing
Distributed data processing is a network of interdependent computers where certain functions are centralized, other functions are decentralized, and processing is shared among two or more computers. It is an alternative to both centralization and decentralization.
A distributed/decentralized processing environment works best when significant volumes of data are generated at many remote locations and the user requires near-immediate access to the data. This type of processing environment will allow for quick access to the data as opposed to having that information generated at many locations and processed at a centralized location.
Distributed data processing provides infrastructure services that facilitate the rapid development, deployment, and management of distributed applications in the telecommunications arena and integrate all telecommunications management and control functions into a unified logical software architecture supported by a single distributed control platform.
Record Count
- A batch record count is the number of records included in the batch where a record is a set of related fields about the same data.
- The records are counted before processing and again after processing, and the two totals are compared to assure that no records are added or omitted.
Invoice No. Product Quantity Unit Price
101 K 10 50 $ 5.00
102 M 15 100 10.00
103 P 20 150 25.00
104 Q 25 200 30.00
105 T 30 250 35.00
These records are in sequence (101, 102, 103, 104, 105) so the number of records is five.
Input devices include
a. Keyboard
b. Image scanner
c. Magnetic ink character recognition (MICR) —a device used to read magnetic ink characters (such as those found on the bottom of checks)
d. Pointing device (graphics tablet, joystick, light pen, mouse, touchpad, touchscreen)
Hash totals
Hash totals are an input control. They are a nonsense total; for example, the sum of the digits of an invoice number. A hash total is similar to a control total and is used to verify processing (or output) compared to input.
Invoice # Product Quantity Unit Price
201 F10 150 $ 5.00
202 G15 200 10.00
203 H20 250 25.00
204 K35 300 30.00
In this case, the total of the invoice numbers (810) has no meaning in itself. However, it can be compared to a total of the invoice numbers computed at a different stage in the processing to provide evidence that all invoices were processed or entered and none were processed or entered twice.
What are the benefits of Electronic Data Interchange?
- Electronic data interchange (EDI) is the exchange of documents in standardized electronic form between different entities in an automated manner directly from a computer application in one entity to an application in another.
- Advantages of an EDI system include reduced errors, costs, and processing time, uses globally-accepted standards, and efficient. It was developed in conjunction with the just-in-time (JIT) inventory system.
What are the characteristics of a Relational Database?
Relational databases are flexible and useful for unplanned, ad hoc queries, do store data in table form, and are maintained on direct access devices
What are the units of computer data from smallest to largest?
- Bit - 1 (on) and 0 (off)
- Byte - 8 bits to a byte/character
- Field - group of related characters/bytes (i.e. Name- Zip Code- Serial #)
- Record - Group of related fields (i.e. Member name- address- phone number)
- File - Group of related records (i.e. Membership directory)
What is a check digit?
An input control that adds an identification number to a set of digits - usually at the end
A check digit is a specific type of input control, consisting of a single digit at the end of an identification code that is computed from the other digits in a field. If the identification code is mis-keyed, a formula or algorithm will reveal that the check digit is not correct, and the field will not accept the entry.
What is a hash total?
An input control number- a meaningless sum of values included in the input.
Example would be summing a list of SSNs to make sure the data is the same once entered as it was prior to input into the system.
Extensible business reporting language (XBRL)
Extensible business reporting language (XBRL) uses tags to identify the contents of each data item. It was created to transmit financial information over the Internet.
