Commercial Data Processing. Lesson 3: Data Validation. By the end of this lesson you will be aware of:. GIGO Validation Verification Check Digit Range Check. The Data Processing Cycle. The Data Processing Cycle.
The Data Processing Cycle
Data must be collected before it can be input. It can be collected in from a source document, such as an order form.
data collection & preparation
Data has to be entered into the computer for processing.
Inputting data directly ie automatically, reduces the mistakes made by people and makes this stage quicker.
Data is processed, ie fed into the program and manipulated. There are 2 types of processing: interactive and batch.
Data is then stored on some form of backing store.
data processing & storage
Processed data is either displayed on a monitor, printed onto paper (often as a turnaround document) or output to a file.
output of data
Verification is the process of checking the datafor complete accuracy.
Validation is the process of checking that the data should be correct and accurate.
A check digit is calculated using the other numbers in the bar code.
Eg 3+2+0+0+0+0+0+0+0+3+7+7=22 divide by 5 = 4.4 so check digit 4
So 4 is added to the end of the bar code 3200000003774.Validation Using Check Digit
The last number of a bar code is a Check Digit.
It is a computer check digit which help to makes sure the bar code read by the reader is correct and accurate.
Validating The Bar Code
IF check digit: scanned = calculatedTHEN
Explain that it is important that data must be correct.
Explain what is meant by GIGO.
Explain the difference between validation and verification.
Give an example of when verification is needed and suggest how it can be done.
Explain how a check digit can be used in validating data.
Explain how a range check can be used in validating data.
Past Paper Question
Read the through information contain in http://www.teach-ict.com/as_a2/topics/validation_verification/verification_validation/validation1.htm