What is an information system?

Source: KCSE Computer Studies 2012 - Paper 1
Question Number: 19 (a)(b)(c) (d) 
Marks: 15 Marks

​(a) (i) What is an information system? (1 mark)

From Topic: System Development
From Subtopic: Definition of an Information System
Question Level: Form 3
​Expected Responses
Information system is an arrangement of people, data, processes, communication and IT that interact to support problem solving.

(ii) State two roles of an information system. (2 marks)

From Topic: System Development
From Subtopic: Purpose of an Information System
Question Level: Form 3
​Expected Responses

1. Improve day-to-day operation
2. Support problem solving
3. Support decision making needs for management
4. Data capture
5. Processing data into information
6. Data security
7. Storing of data/information

(any 2 for 2 marks)

​(b) Describe the following file organisation methods:

(i) random file organisation; (2 marks)
From Topic: Data Processing
From Subtopic: File Organization Methods
Question Level: Form 3
​Expected Responses
Stored and retrieved according to their disk address which is generated by use of an algorithm or formula i.e. stored randomly, accessed randomly. (2 marks)

(ii) sequential file organisation. (2 marks)
​Expected Responses
​Method of storing or retrieving information that requires the program to start
reading at the beginning and continue until it finds the desired data. (2 marks)

​(c) The following records were extracted from two files that contained student data.

From Topic: Database / Data processing
From Subtopic: Types of Computer Processing files
Question Level: Form 3

(i) Which of the two files above represents a Transaction file? (1 mark)
​File B.
(ii) Give a reason for your answer in c(i) above. (1 mark)
Transaction file: It contains data which is regularly added.
​Has data/fee payment
​(iii) Name the other type of file represented above. (1 mark)
Master File: It contains records that do not change regularly like in file A.

​(d) An airline uses an information system whereby if a passenger at station A books a plane seat, this transaction is immediately shown at stations A and B such that no other passenger can book the same seat.

From Topic: Data processing
From Subtopic: Electronic Data Processing Modes
Question Level: Form 3

(i) Identity this data processing mode. (1 mark)
Real Time Processing

(ii) State two advantages and two disadvantages of this data processing mode. (4 marks)
(ii) Advantages

1. Information is readily available for instant, decision making.
2. Updating is clone instantly when transaction occurs.
3. Auditing is easier.
4. It is accurate
5. Prevent double booking

(any 2 x 1 =2 marks)

Disadvantages

1. Complex - difficult to configure/setup.
2. Expensive to acquire and maintain.
3. Errors that occur are difficult to correct

(any 2 x I = 2 marks)

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