Data and quality of data

Data - raw facts/figures (no meaning)
Data + meaning = information
information + understanding = knowledge
Data can be numbers, words, pictures, videos and sounds
Data goes into a computer and useful information comes out
must be good quality
1. GIGO - Garbage in Garbage out
  1. Incorrect data goes in = incorrect information comes out
Quality of data
1. Fit for purpose
  1. Asking for someones religion is NOT fit for purpose
2. Accurate
  1. incorrect items could be delivered if data isn't accurate
3. Up to date
  1. Correct address so products can be delivered
4. Valid
  1. Ordering food in B&Q won't be valid data
5. Non-biased
  1. Collecting data from a random sample
Data validation
1. Data needs to have NO ERRORS
  1. Validation spots the errors
    1. Types of errors
      1. Wrongly recorded
        Data capture forms designed to minimise errors
      2. entered incorrectly
        double keyed or proof read
      3. Could be changed by unauthorised personel
        security (passwords)
      4. Corrupted during transmition
        encryption
2. checks data BEFORE processed
Data Verification
1. Checks data AFTER being processed
validation techniques
1. Range check
  1. numerical data lies within an acceptable range
    1. 1-31 DAYS OF THE MONTH
2. presence check
  1. is any data missing?
3. Format check
  1. Data in correct format
4. Check digit
  1. Calculation creates an extra digit
    1. computer checks that the check digit is correct when data is entered

Resource summary

	Created by Matthew Stentiford about 7 years ago