Data Management

1
Data Management

• Data Verification
• Data Validation

2
Data Verification

• Double Entry
• Parallel Entry
• Verify against the original source

3
Double Entry
Please Enter Your Password

Re-enter your password

Sorry! Not the same. Please re-enter!
4
Double Entry
Please Enter Your Password

Re-enter your password

5
Parallel Entry
246879
246789
246789
6
Verify with original
Enter you student number
9801234
Student Card No 9801234 Name Chan
ching Sex F
Correct ?
YES
NO
7
Data Validation

• Type Check
• Range Check
• Presence Check
• Control Total Check
• Check Digit

8
Type Check
Name
Le0n La1
Invalid
9
Range Check
Date of birth
32/13/1986
Invalid
10
Presence Check
Name
Leon Lai
Invalid
Date of birth
23/3/1986
Student Number
Sex
F
11
Control Total Check
Total number of students in class 40
DATA
Invalid
Number of records processed 39
12
Check Digit- weighted modulo 11 method
Use the ID no E453712(x) as an example
X 14 11 - (58 47 56 35 74 13
22) 154 - 148 6
Valid ID no E453712( )
6
13
Verification vs Validation

• Verification
• Make sure the data entered is the same as the
  source

• Validation
• Make sure the data entered meets the specified
  criteria
• Name must be letters
• Months must be 1 12
• All necessary fields must be present e.g. student
  no.
• Numbers must match with the check digit

14
Web reference

• http//www.webopedia.com/
• http//www.ora.com/reference/dictionary/