Data and quality of data

Data and quality of data

1. Data - raw facts/figures (no meaning)

2. Data + meaning = information

3. information + understanding = knowledge

4. Data can be numbers, words, pictures, videos and sounds

5. Data goes into a computer and useful information comes out

6. must be good quality

   • GIGO - Garbage in Garbage out
     • Incorrect data goes in = incorrect information comes out

7. Quality of data

   • Fit for purpose
     • Asking for someones religion is NOT fit for purpose
   • Accurate
     • incorrect items could be delivered if data isn't accurate
   • Up to date
     • Correct address so products can be delivered
   • Valid
     • Ordering food in B&Q won't be valid data
   • Non-biased
     • Collecting data from a random sample

8. Data validation

   • Data needs to have NO ERRORS
     • Validation spots the errors
       • Types of errors
         • Wrongly recorded
           • Data capture forms designed to minimise errors
         • entered incorrectly
           • double keyed or proof read
         • Could be changed by unauthorised personel
           • security (passwords)
         • Corrupted during transmition
           • encryption
   • checks data BEFORE processed

9. Data Verification

   • Checks data AFTER being processed

10. validation techniques

    • Range check
      • numerical data lies within an acceptable range
        • 1-31 DAYS OF THE MONTH
    • presence check
      • is any data missing?
    • Format check
      • Data in correct format
    • Check digit
      • Calculation creates an extra digit
        • computer checks that the check digit is correct when data is entered