Data and information

Data and information

1. DATA

   • Data (DEF) Data is a set of raw facts and figures that have no been given context or meaning

2. Information

   • Information (DEF) information is processed data that has been given content and meaning
   • INFORMATION = DATA +CONTEXT+MEANING

3. Knowledge

   • Knowledge (DEF) Knowledge is the application of information
   • Knowledge is the ability to form judgements and decisions based on information

4. QUALITY OF INFORMATION

   • Accuracy - Info should be error free (validation and verfication used to ensure this)
   • Relevance - Information being collected should be relevant, otherwise irrelevant information can be a waste of time and information overload
   • Completeness - There shouldn't be any information missing
   • Age - Information should be up to date and should not relflect previous findings
   • Presentation - Information should be presented in an appropriate format (graphs eg.)
   • Transcription Errors
     • Omission Errors
       • When information IS LEFT OUT
     • Transposition errors
       • When the correct information is keyed in but in the WRONG ORDER

5. VALIDATION TECHNIQUES

   • Presense check: Ensures that sensitive (vital) data is entered and that fields arent left blank.
   • Length Check: make sure the data is of the a specified length (correct character limit)
   • Type check: Ensures data is of a particular type e.g. numeric, text, boolean, date, time etc
   • Range Check: Ensures that data falls between an upper and lower numeric boundary and data entered outside of this boundary will be rejected.
   • Format Check: Checks that data matches a pre set layout
   • Look-up table: A table that has a set of valid options to choose / Select from

6. Verification Techniques

   • Double Entry : Data is entered twice and system checks that both version match.
   • Proof reading: The person inputting the data reads over the data and ensures data inputted is as intended
   • Purpose of verification
     • Verification is carried out by a HUMAN to ensure data which has been input has been accurately transfered from the source document to the computer.
       • Done with DOUBLE ENTRY and PROOF READING

7. Check Digit

   • Is an extra digit added onto the end of a number.
     • The check digit can be calculated using the other numerical digits using weightings.
   • Check digit is used to make sure a range off numbers have been inputted correctly
   • The computer will automaticly perform a complex calculation to ensure the other digits make up the check digit to ensure the number entered is correct
   • How to calculate modulus 11 (check digit)
     • You firstly write out your code 46138 You then multiply the code by your weightings (beginning with 2 going right to left) 4    6    1    3   8 x6 x5 x4  x3  x2 2 30 4   9   16 You must then add the result of your weightings together. 24+ 30 + 4 + 9 + 16 = 83 Then you must divide the total of your weightings by 11 83/11 = 7 Remainder 6 You must then take the remainder away from 11 11 - 6 = 5 The check digit is 5 NOTE) If the remainder is 0 the check digit is 0  If the remainder is 10 the check digit is X