Topic 7

Question 1

What is linear search [3]

Answer 1

A method that inspects each item in a list
-in turn
-to see if the item matches the value searched for

Question 2

What is bubble sort? [5]

Answer 2

A method that compares each element with the next
-to swap if they are in the wrong order
-starting from the first element and finishing with the second last element
-compare again except last element because it is correct
-repeat until it reaches one element left

Question 3

What does validation do? [2]

Answer 3

-ensure that only data that is reasonable is accepted
-reject unreasonable data and explains reason

Question 4

What does verification do?

Answer 4

check that the data is accurately copied from one source to another

Question 5

What types of verification are there? [2]

Answer 5

-double entry
-screen/visual check

Question 6

What types of validation are there? [6]

Answer 6

-presence check
-type check
-range check
-length check
-check digit
-format check

Question 7

Explain range check

Answer 7

checks that the value is between an upper value and a lower value

Question 8

Explain length check

Answer 8

checks the number of characters in a data

Question 9

Explain Type check

Answer 9

checks data entered is certain type of data eg. integer, string

Question 10

Explain Presence check

Answer 10

checks that some data has been entered and the value hasn’t been left blank

Question 11

Explain format check

Answer 11

checks data entered conform to a pre defined pattern

Question 12

Explain check digit

Answer 12

final digit included in a code calculated from all the other digits to indentify errors

Question 13

Explain double entry

Answer 13

when data is entered twice, checked if they are identical, and output error message if they aren’t

Question 14

Explain screen/visual check

Answer 14

when user is asked to confirm data entered after data is displayed

Question 15

Explain set of test data

Answer 15

all the items of data required to work through a solution

Question 16

Explain normal data

Answer 16

set of test data that an algorithm is expected to work with

Question 17

Explain abnormal test data (erroneous test data)

Answer 17

a test data that would be rejected by an algorithm as not suitable

Question 18

Explain extreme data

Answer 18

largest and smallest values that normal data can take

Question 19

Explain boundary data

Answer 19

two values: one rejected, one accepted to establish where the extreme data occur

Question 20

Explain trace table

Answer 20

used to record the results from each step in an algorithm

Question 21

Explain dry run

Answer 21

the manual exercise of working through an algorithm step by step