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Section 5: Information Processing Check your progress 1

1. In the examples given on page 227, which are automation systems and which are process control systems?

A. Automation systems: manufacturing chemicals, packing goods, video recorders, digital televisions, digital cameras, washing machines, microwave ovens, cell phones.

Control systems: Robots for manufacturing, signalling systems, autopilots, driverless trains, fuel injection systems.

End-of-topic questions 1

1. Explain the difference between data and information.

A. Data is input into an information system, which then processes it and produces useful information.

2. List three ways in which data can be processed.

A. Any three from: calculating, printing, searching, updating, displaying, sorting

3. What kind of proprietary software packages could be used for each of these tasks:

a. Correspondence

b. Accounts

c. Budgeting

d. Marketing

A. a. word processing

b. accounting package, spreadsheet

c. spreadsheet

d. desktop publishing

4. Explain the differences between automation and process control systems.

A. Automation and process control systems both use computers to control actions; automation systems are simpler and work

automatically, whereas process control systems respond to input from sensors.

5. What kind of software could be used by a scientist to analyse and present their findings?

A. Spreadsheet

Check your progress 2

1. What are the advantages of using machine-readable documents for inputting data in a computer system?

A. Machine-readable documents can be scanned by an input device without any human intervention, which will make the

input process both faster and more accurate.

End-of-topic questions 2

1. What is a turnaround document?

A. A turnaround document is one that is printed by a computer system, but is later used to input new data into the same

system.

2. What are the advantages of using machine-readable documents?

A. Input will be faster and more accurate than a person reading and keying in data.

3. Why do forms sometimes make you write each character in a separate box?

A. So that each character can be clearly read by the person who is keying in the data.

Check your progress 3

Mr.Ramjagasar

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1. An employee was keying in data written on an application form. Which of these errors could be identified by data verification, which by

data validation, and which by neither?

a. Year of birth is given on the form as 2003 but entered as 2103.

b. Year of birth is given on the form as 1894.

c. Surname is very indistinct on the form; it could be Davis or Davies.

d. The Town of Birth is given on the form as 256.

e. The address given on the form does not exist.

A. a. Data verification

b. Data validation

c. Neither

d. Data validation

e. Neither (although data validation could identify this error if it the system allowed it to check against a list of

addresses)

End-of-topic questions 3

1. What is the main difference between data verification and data validation?

A. Data verification is carried out by a person; data validation is carried out by software.

2. Why is it better to use double entry for data verification rather than simply checking over what has been entered?

A. Because a second person is more likely to spot any errors.

3. Describe three methods of data validation.

A. A range check will check whether numerical data is within certain limits. For example, if an age has been entered, then a

range check will spot an error if the age lies outside the range 0 to 100.

A data type check will check whether the data is of the correct type, such as number, date or text. For example, an

age should be entered as a number not as text.

An inconsistency check will compare two or more data items. For example, if someone has given their title as Mr then they should

have entered their gender as Male.

End-of-topic questions 4

1. Explain the difference between sequential and direct file access.

A. Sequential access to data is used when the data has to be read from the start, in sequence. It is the normal method of

access for magnetic tape. Direct access is used when it is possible to jump directly to a file or data item without reading

through all the items stored before it. This is the normal method used for hard disks.

2. When considering files of records, what is a record?

A. A record is a set of all the data about a single item in a file.

3. What is a sort key?

A. A sort key is a field that is used to determine the sort order of a file of records.

4. Give an example of a file that would be organised sequentially.

A. Examples could include: list of students in a class, club membership list.

End-of-topic questions 5

1. What is the role of an index file in index-sequential file organisation?

A. An index file is used with a sequential file that has been sorted using a sort key. The index file gives the position of

significant records in the sequential file, such as the first record that begins with a specific letter in the sort field.

2. Of the three methods of file organisation (sequential, index-sequential and random) which, if any:

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a. can only be used with direct access media?

b. can be used with both direct access and sequential media?

c. can only be used with sequential media?

A. a. Indexed-sequential and random

b. Sequential

c. None

End-of-section questions

Multiple-choice questions

1. The following are statements about data.

I. They are raw facts

II. They can be processed to form information

III. They are results of processing

IV. They can be numbers or characters

Which statements are true?

A I, II and III only

B I, III and IV only

C I, II and IV only

D I, II, III and IV

A. C

2. All of the following are examples of business information activities except:

A Payroll

B Accounts

C Archiving

D Budget

A. C

3. Which of the following devices would most likely be present in a process control system?

A Robots

B Sensors

C Digital assistants

D Spreadsheets

A. B

4. Which of the following is a machine-readable document?

A A handwritten letter

B Output from a speaker

C A barcode

D All of the above

A. C

5. All of the following are validation checks except:

A Consistency check

B Range check

C Accuracy check

D Data type check

A. C

Structured questions

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1. a. State the difference between data and information.

b. Define the term information processing.

c. List three forms of information processing.

A. a. Data is raw facts given to the computer for processing; information is meaningful facts after

processing.

b. Information (or data) processing refers to computer-based systems that take in data and generate

information.

c. Commercial data processing; industrial data processing; control systems;

scientific data processing

2. a. Briefly explain how a process control system works.

b. Give one example of a process control system.

A. a. In process control systems, data is captured automatically using sensors. The

software in the controller then processes the data from the sensors and determines what action, if any, to

take. It then sends the instructions to other special devices such as motors and switches,

which are part of the device that is being controlled.

b. Robots, air conditioning control system for a large building

3. a. State the difference between a source document and a turn around document.

b. Give one example of a machine-readable document.

c. Give one example of a human-readable document.

A. a. A source document is one that contains data that is going to be input into a computer system. A

turnaround document is one that is printed by a computer system, but is later used to input new data into the same

system.

b. A multiple-choice answer sheet to be read by OMR; a bill to be read by an OCR; a photograph to be read

by a scanner.

c. A print-out on paper; a hand-written form.

4. a. Distinguish between data validation and data verification.

b. List three ways in which data can be validated.

c. Briefly describe any two of the types of data validation you identified in your answer Q4b.

A. a. Data verification is the process of checking to ensure that data has been correctly

keyed into a computer system while data validation is the process to identify data that cannot be correct, when data

is entered.

b. Range checks, data type checks, inconsistency checks

c. Range checks - these check whether numerical data is within expected limits.

Data type checks - these check whether the data is of the correct type, such as number, date, or text.

Inconsistency checks - these check one piece of data against another.

5. a. List three methods of file organisation.

b. For each of the methods of file organisation you identified in your answer to Q5a, give one example of an application

where it is used.

c. State the difference between sequential access and direct access.

A. a. Sequential; indexed-sequential; random

b. Sequential in archiving using magnetic tapes, sorted transaction file of a company

Indexed-sequential employee records in database

Random any information retrieval system e.g. flight information system

c. Sequential access is retrieving information in the same order it is physically stored,

and the time taken to retrieve the information is dependent on its physical location. Direct access is

retrieving information in any order and the time taken to retrieve the information is

not dependent on its physical location.