IGCSE COMPUTER SCIENCE PAPER #2
EXAM GUIDE QUESTIONS AND
ANSWERS
Algorithm - Answer-a step-by-step procedure for solving a problem
Computer system - Answer-A five-part system consisting of hardware, software, data,
and people and communications
Normal data - Answer-Entering data that should be acceptable to the solution.
Abnormal test data - Answer-Test data that is clearly incorrect and should produce an
error.
Extreme data - Answer-Test data on the boundary of what the program will accept
Boundary data - Answer-Data either side of the range extremes. For example in a range
of 1 to 10 boundary data will include 0, 1, 10 and 11
Validation - Answer-Is the automated checking by a program that data is reasonable
before it is accepted into a computer system.
Range check - Answer-checks that only numbers within a specified range (upper and
lower limit) are accepted.
E.G. percentage marks between 0-100 ONLY
Length Check (2) - Answer-1. Checks that data contains an exact number of characters.
E.G. that a password must by exactly 8 char in length.
2. That the data entered is a reasonable number of character e.g. Family name should
be between 2-30 char
Type check - Answer-checks that the data entered is of a given data type. E.G. number
of brothers or sisters would be an integer (whole number)
Character check - Answer-checks that when a string of characters is entered it doesn't
contain any invalid characters or symbols. E.G. Doesn't contain % or !@£ in a phone
number
Format check - Answer-checks that the character entered conform to a pre-defined
pattern. E.G.the Cub number must be in the form CUB9999
EXAM GUIDE QUESTIONS AND
ANSWERS
Algorithm - Answer-a step-by-step procedure for solving a problem
Computer system - Answer-A five-part system consisting of hardware, software, data,
and people and communications
Normal data - Answer-Entering data that should be acceptable to the solution.
Abnormal test data - Answer-Test data that is clearly incorrect and should produce an
error.
Extreme data - Answer-Test data on the boundary of what the program will accept
Boundary data - Answer-Data either side of the range extremes. For example in a range
of 1 to 10 boundary data will include 0, 1, 10 and 11
Validation - Answer-Is the automated checking by a program that data is reasonable
before it is accepted into a computer system.
Range check - Answer-checks that only numbers within a specified range (upper and
lower limit) are accepted.
E.G. percentage marks between 0-100 ONLY
Length Check (2) - Answer-1. Checks that data contains an exact number of characters.
E.G. that a password must by exactly 8 char in length.
2. That the data entered is a reasonable number of character e.g. Family name should
be between 2-30 char
Type check - Answer-checks that the data entered is of a given data type. E.G. number
of brothers or sisters would be an integer (whole number)
Character check - Answer-checks that when a string of characters is entered it doesn't
contain any invalid characters or symbols. E.G. Doesn't contain % or !@£ in a phone
number
Format check - Answer-checks that the character entered conform to a pre-defined
pattern. E.G.the Cub number must be in the form CUB9999
