Validation & Verification

Question 1

Name 3 errors when inputting data.

Answer 1

Transcription errors
- typing in the wrong character by accident e.g. 2 instead of 3

Transposition errors
- keying in the wrong order e.g. 1243 instead of 1234

Data entered in wrong format
E.g. YYYY/MM/DD instead of DD/MM/YYYY

Data scanned in incorrectly
E.g. Due to barcode or OCR form being damaged

Question 2

What are Processing errors and Transmission errors.

Answer 2

Processing Errors
- There are errors in the software which will result in the data being processed incorrectly

Transmission Errors
- When data is being sent from one computer to another data may become corrupted or sections may be lost

Question 3

Define Validation and Verification

Answer 3

Validation is the process of ensuring data is legal and sensible

Verification is the process of checking that data has been correctly copied from one media to another

Question 4

Describe 3 methods of Validation with examples.

Answer 4

Range Checks
- data is between stated ranges e.g. Pupils ages must be between 10 and 19

Format Checks
- data must be in the correct format e.g. Date must be 12/04/17 not 12-April-2017

Presence Checks
-There must be data present in a particular place e.g. The password field cannot be left blank

Data type check
- If a number was required a string would be rejected e.g. The word eight in an age field instead of 8

Check digits
- number added to code to ensure data is entered correctly e.g. Bar codes on library tickets

Question 5

Describe 3 methods of data verification.

Answer 5

Proof reading
- This involves reading over data to make sure that it has been entered correctly

Double Entry
- used when it is essential that the data is correct, involves entering the same data twice e.g. Password

Sending back printouts