Topic 4: Validation and Verification

Question 1

What is validation of data?

Answer 1

Validation is a process that ensures data being put into a system is sensible and reasonable.

Question 2

A process that ensures data being put into a system is sensible and reasonable is what?

Answer 2

Validation of data.

Question 3

Name and describe how one validation method could be used in a website registration form.

Answer 3

Name: A software developer will write a short piece of code that prevents data being entered if it doesn’t fit certain rules.

Describe: A website registration form would require a presence check for essential fields such as name and address.

A format check could be used to make a date of birth is entered as DD/MM/YYYY.

A range check could be used to ensure that the year of birth makes sense for an adult between the ages of 16 - 99.

Question 4

A presence check is a type of what method?

Answer 4

Validation

Question 5

A format check is a type of what method?

Answer 5

Validation

Question 6

A range check is a type of what method?

Answer 6

Validation

Question 7

What is a presence check?

Answer 7

Occurs for essential fields on forms, i.e. name and address.

Question 8

What is a format check?

Answer 8

Occurs to make sure that the format of information is correct, i.e. to make sure that a date of birth is entered as DD/MM/YYYY.

Question 9

What is a range check?

Answer 9

Occurs to make sure that information makes sense, i.e. to make sure that a year of birth makes sense for an adult between the ages of 16-99.

Question 10

Give an example of data validation in a website registration form that requires ‘presence’.

Answer 10

A website registration form usually has a validation check which prevents someone from leaving if they have left a essential field blank. These would likely be things like first name, or address.

Question 11

What is verification of data?

Answer 11

A verification check involves comparing two sources of the same data to ensure they are identical.

Question 12

A process that involves comparing two sources of the same data to ensure they are identical is known as what?

Answer 12

Verification check.

Question 13

What is an example of a verification check?

Answer 13

An example of a verification check is needing to enter a new password twice. This is also known as double entry.

Question 14

Needing to enter a new password twice is an example what kind of what kind of check?

Answer 14

Verification check.

Question 15

An employee proof reading data on a computer to ensure it is the same as the original paper source is an example of what kind of verification?

Answer 15

Manual verification.

Question 16

Give an example of manual verification.

Answer 16

An example of manual verification is an employee proof reading data on a computer to ensure it is the same as the original paper source.

Question 17

Why are validation checks and verification checks necessary?

Answer 17

Validation and verification checks are necessary in order to reduce the number of errors that get into a data system. The aim is to reduce the problem of GIGO.

Question 18

Define GIGO (Data, Information, and Knowledge)

Answer 18

Garbage
In
Garbage
Out

Question 19

Do validation and verification checks ensure data input into a system is perfect?

Answer 19

No, it is impossible to ensure that data held on a computer is 100% perfect.

There will always be some errors that get through because not everything can be checked.

Question 20

If a developer is very careful to code plenty of validation and verification checks, can they be sure that all customer addresses are correct?

Answer 20

No. This is because only the customer knows if their address is old or new/current.

If the customer is asked to confirm their address, however, this is a better verification check.

Question 21

A check which occurs to see if a postcode is not longer than 8 characters is called what?

Answer 21

A length check.

Question 22

A check which occurs to see if the first and last name are completed is called what?

Answer 22

A presence check.

Question 23

A check which occurs to see if someones age is between 12 and 100 is called what?

Answer 23

A range check.

Question 24

A check which occurs to see if a username is taken or not is called what?

Answer 24

A file/table look-up.

Question 25

A human error is known as what kind of error?

Answer 25

A transcription input error.

Question 26

What is a transcription input error?

Answer 26

A human error.

Question 27

Give two examples of a transcription input error.

Answer 27

Occurs due to a typing mistake

or

Misreading handwriting.

Question 28

What check can be used to detect transmission errors?

Answer 28

Parity check.

Question 29

A parity check is sometimes used to detect what kind of errors?

Answer 29

Transmission errors.

Question 30

Describe how even parity is used to detect transmission errors.

Answer 30

The binary code for the ASCII character ‘C’ contains three ones (1000011). An extra parity bit is therefore set to 1 before transmission so that the number of ones is even. This is called ‘even parity’. If after this the total number of ones at the receiving end is not even then an error must have occurred,

Question 31

An error check that notifies the consumer that the long credit card number must not have letters of special characters is called what?

Answer 31

A type validation check.

Question 32

An error check that notifies the consumer that their postcode does not match their billing address is known as what?

Answer 32

A cross-field validation check.

Question 33

An error check that notifies the consumer that their password entries do not match is known as what?

Answer 33

A verification check.

Question 34

An error check that notifies the consumer that they must enter their email in the form xxx@xxx.xx.xx is known as what?

Answer 34

A format check.