Chapter 1

Chapter 1

1. Data & Information

   • Data types
     • Alphanumeric (text/string)
     • Graphics
     • Sound
   • Processing
     • Structure - how data is organised or formatted
     • Context - Prior knowledge and understanding
     • Meaning - Data is within the correct structure and context
   • Definition
     • Data - Random facts and figures without meaning e.g. 12102005
     • Information - Processed data

2. Representation methods

   • Sound
     • No LOS or fixed position required
     • No problem for visually impaired
     • Not useful in large areas
   • Graphics
     • multi-lingual
     • can match real life image
     • Confusing without context
     • Symbols can mean different things
   • Text
     • Clear to understand
     • High level of detail
     • Language barriers
     • difficult at a distance
     • Can be confusing
   • Moving pictures (animations)
     • Lots of information
     • Not language dependant
     • Linear - may require the beginning to make sense
     • Issues if linked with sound
   • LED's
     • Can be used in noisy places
     • Similar to graphics
     • Need LOS
     • Combinations will require context

3. Data Types

   • Number
     • Real - decimal places or fractions e.g. 10.5 0.0003
     • Integer - no decimals or fractions e.g. 3, 157
   • Date/Time
     • Formatted into date/time with variations e.g. US and UK dd/mm/yyyy
   • String/Text
     • Alphanumeric can be words, numbers or symbols (phone numbers) e.g. 07511 262 756
   • Boolean
     • Yes/No, On/Off 0,1 values
   • Primary/Secondary
     • Primary - Self collected for a specific purpose
     • Secondary - Collected by someone else for a different purpose

4. Data Sources

   • Static - Information that once published, can not be changed e.g. a book
     • Greater checks for accuracy
     • Can be used without computer access
     • Historical copies can be referred back to
     • Can be damaged or lost, with only one copy
     • Takes longer to produce e.g. publishing
     • Mistakes are difficult to correct
   • Dynamic - Information that can be changed after publishing
     • Quick to produce
     • Easy to correct mistake
     • New copies can easily be issued
     • Checked for accuracy less often
     • Need internet access
     • No historical version

5. Quality of information

   • Accuracy
   • Relevance
   • Level of detail
   • Age
   • Completeness
   • Presentation

6. Verification - checks that data corresponds with the original copy

   • Double entry - entering data twice and the computer checks if they match
   • Manual verification - Checking the data against a hard copy
   • Errors
     • Transcription - adding or missing a letter
     • Transposition - When you have reversed 2 numbers or letters

7. Validation - Checking that data is plausable

   • Range check
   • Picture Check
   • Type Check
   • Presence Check
   • Length Check
   • Lookup Check
   • Check Digit

8. Backup and archiving

   • Backing up is saving a copy to another location
   • Archiving is storing the data offsite, you don't currently need those files but may be useful later on (makes room for new data)

9. Cost of producing information

   • Hardware - Printers, monitors etc. and maintenance
   • Software - Graphics and documents sometimes subscription fee
   • Consumables - Paper, ink etc.
   • Personnel - Employees and staff salaries/wages

10. Feedback Loop

    • • • Output
          • Feedback
            • Input
        • Storage
          • Processing
    • Turnaround document

11. Encoding - changing its representation via abbreviation

    • Easier to validate
    • Security
    • Speed of input
    • Less precise
    • Need knowledge of code
    • Limited number of codes