Chapter 1

Chapter 1

1. Data, information and knowledge

   • Data is made up of alphanumeric charters
   • Information = data+structure+context+meaning
   • Knowledge is the application of information to a situation

2. Representation methods

   • Text
     • + clear to understand
     • - need to be able to read
   • Graphics
     • + multilingual
     • - can be confusing of you don't know the symbols
   • Sound
     • + no fixed position
     • - usually language based
   • Animation/Video
     • + Not language dependent
     • - may need to see the end beginning to understand
   • LED
     • + can allow data to be kept secure
     • - need to be able to see lights

3. Date types

   • Boolean: true or false
   • Real: numbers with decimals
   • Integer: whole numbers
   • Text/String: alphanumeric characters
   • Date/Time

4. Sources of data

   • Indirect data
     • Either collected by someone else or used for a purpose different to the original
     • + large range of data is available that could not have been collected directly
     • - do not know if any bias was placed on the collection
   • Direct data
     • Data collected by you
     • + the source and collection method is known and verified
     • - data may not be available (location/time)

5. Static and dynamic data

   • Static data
     • Cannot be changed
     • + does not require internet access
     • - limited amount of information available
     • - can be lost/stolen or broken/scratched
   • Dynamic data
     • Can be updated
     • + provides a large volume of information
     • - only people with internet access can access the information
     • + provides many different opinions

6. Quality of information

   • Accuracy
     • If the information in not accurate you can't rely on it
   • Relevance
     • Information that does not relate to the topic is worhtless
   • Age
     • Information can change over time
   • Presentation
     • Information loses value if you can't understand it or find what you want
   • Level of Detail
     • The volume of data determines whether you have enough to make a decision or too much
   • Completeness
     • If you only have part of the information it is worthless

7. Validation and Verification

   • Validation
     • Ensures that entered data is reasonable, complete, sensible and within acceptable boundaries
     • Range check
     • Type check
     • Presence check
     • Lookup check
     • Check digit
     • Length check
     • Picture check
   • Verification
     • Ensures the source and the object data are the same
     • Manual verification
     • Double entry
     • Common errors
       • Transcription: entering the wrong data
       • Transposition: entering data in the wrong order

8. Cost of information

   • Hardware
     • Initial costs
     • repair/maintenance costs
   • Software
     • training costs
     • upgrades
   • Personnel
     • employee eages
   • Consumables
     • items that get used
     • paper/printer ink

9. ICT systems

   • Input
     • Entering external information into the system
   • Processing
     • Actions performed on the data (sorting, searching etc)
   • Storage
     • Where data is held
   • Output
     • Outputting information from the system
   • Feedback
     • output forms part of the input
   • Turnaround doouments
     • Additional information recorded on an output which is then input into the system again

10. Backup and Archive

    • Backing up is making a copy of the data
    • Archiving is removing data from direct access

11. Encoding

    • Storing data in a different representation by putting it into code
    • + less memory required
    • + increased security
    • + increased speed of input
    • - precision of data coarsened
    • - the user needs to know the codes used
    • - limited number of codes