Purpose and Types of Validation

Purpose and Types of Validation

1. Validation is one way of trying to reduce the number of errors in the data being entered into your system. The validation is performed by the computer at the point when you enter data.

   • Validation aims to make sure that data is sensible, reasonable, complete and within acceptable boundaries.

2. There are two types of data entry when using a keyboard can be put into two groups

   • Transcription errors
     • A transcription error is a specific type of data entry error that is commonly made by human operators or by optical character recognition programs.
   • Transposition errors
     • A transposition error is a simple error of data entry that occurs when two digits that are either individual or part of a larger sequence of numbers are accidentally reversed (transposed) when posting a transaction.

3. A transcription error is as a result of reading wrongly the values or letters to be input, whereas a transposition error is as a result of interchanging the positions of correct letters or values.

4. Types of Validation checks

   • Data type checks
   • Presence checks
   • Length checks
   • File/Table lookups
   • Cross field checks
   • Range checks
   • Format checks

5. Ways errors can be reduced

   • Reduce the amount typed in (encoding)
   • Use a range of validation and verification methods
   • Let users check their details
   • Let users type in their own details to avoid confusion

6. Types of transposition errors

   • 'fro' instead of 'for'
   • '10065' instead of '10056'
   • Flight number 'AB376' instead of 'BA376'

7. Types of transcription errors

   • Problems with understanding speech
   • Poor handwriting
   • Misinterpretation
   • Typing mistakes