Paper 2

Question 1

What are the 4 stages of program development life cycle (4)

Answer 1

Analysis

Design

Coding

Testing

Question 2

Features of analysis (4)

Answer 2

Abstraction

decomposition of problem

Identification of problem

Requirements

Question 3

Features of design (4)

Answer 3

decomposition

structure diagrams

Flowcharts

Pseudocode

Question 4

Features of coding (2)

Answer 4

Writing program code

iterative testing

Question 5

Feature of testing

Answer 5

Testing program code using test data

Question 6

Explain computer systems (3)

Answer 6

Computer systems range from small and simple to large and complex

Almost all computer systems can be broken down into sub-systems. These sub-systems can typically be broken down into further sub-systems

Eventually, each sub-system performs a single task or action

Question 7

Define decomposition

Answer 7

Breaking a complex problem into smaller, more manageable parts

Question 8

Advantages of decomposition (2)

Answer 8

Makes problems easier to solve

Different people can work on different parts of a problem at the same time, reducing development time

Question 9

Define algorithm

Answer 9

specific sequence of steps that can be followed to complete a task

Question 10

Define computer program

Answer 10

Implementation of an algorithm

Question 11

Define input validation

Answer 11

checking that data input by user meets specific criteria/rules before processing

Question 12

What are the different types of input validation checks (5)

Answer 12

Type check

Range check

presence check

Format check

length check

Question 13

Explain type check

Answer 13

The input is of the correct data type

EG: integer, real, string

Question 14

Explain range check

Answer 14

The input is within a predetermined range

EG: between 1 and 10

Question 15

Explain presence check

Answer 15

All required data has been entered

Question 16

Explain format check

Answer 16

The input is in the correct format

EG: DD/MM/YYYY

Question 17

Explain length check

Answer 17

The input includes the correct/minimum/maximum number of characters

EG: password

Question 18

Advantages of input validation techniques for a programmer (2)

Answer 18

Make their program robust and user friendly

Prevent further errors from occurring later in the program

Question 19

Define verification

Answer 19

Ensures data is not changed either accidentally or on purpose, as it is entered

Question 20

Two methods of verification (2)

Answer 20

Double entry

visual check

Question 21

Explain double entry verification (2)

Answer 21

process whereby important data has to be entered twice

The system then compares both data entry to check they are the same before accepting the data

Question 22

Explain visual check

Answer 22

Manual check performed by the user who is entering the data

Question 23

What are the 4 types of test data

Answer 23

Normal

Abnormal

Extreme

Boundary

Question 24

Explain normal test data

Answer 24

Data that should be accepted without causing any errors

Question 25

Explain abnormal test data

Answer 25

Data that should be rejected by the program (includes when no input is made)

Question 26

Explain boundary test data

Answer 26

Data that is the largest/smallest acceptable value as well as the corresponding largest/smallest rejected value

Question 27

Explain extreme test data

Answer 27

Data that is the largest/smallest acceptable value

Question 28

Define variable

Answer 28

Value stored in memory that can change while the program is running

Question 29

Define constant

Answer 29

A value is assigned when the program is first written and doesn't change while it is running

Question 30

Explain procedures (2)

Answer 30

Carries out a task provides structure to the code

Question 31

Explain Function (2)

Answer 31

Carries out a task and returns a value Creates reusable program components