Embedded Files
Data is captured (input) into computers in a varity of ways both manually and automatically
Information systems depend on:
The correctness of data or Data Integrity
Data held in a computer system may become incorrect, corrupted or of ‘poor quality’.
The main problem is quality of data input
Data input needs to be checked.
Validated to see if it is reasonable and
Verified to correct
Validation:
is a check that data entered is plausible and follows rules set up for the data
e.g. Date of Birth = Banana.
Height = 61 Meters
Verification:
Checking that the sensible data entered is what was supposed to be entered
e.g. Enter data twice or
2nd person / entry checks -(Enter password twice)
Types of Validation (f)
Presence Check
Is the data present.
i.e. not left blank (e.g.Name: Fred)
Format Check
Is the data in the correct format?
Date Of Birth: 12.03.1977
Length Check
Does the data match a known Length?
e.g. Credit card No or telephone number
Range Check
Is the data Within normal acceptable range?
Age = 133
Check Digit
Does the data match a number calculated from itself using a set algorithm.
e.g. Credit cards, Bar code No# ISBN numbers
3.1.3
Data: Its representation, structure and management of information systems
f. Explain the techniques of validation and verification,
and describe validation tests which can be carried out on data.
Validation & verification of data
Page updated
Google Sites
Report abuse