Chapter 1

Chapter 1

1. Data

   • Data sources
     • Dynamic
       • Need internet, not always reliable
       • Can change
     • Static
       • Does not change
       • Limited information
     • Direct
       • Physically collected by user
       • Not a large range, not always available
     • Indirect
       • Collected by someone else and used for a different purpose
       • Not certain of accuracy
   • Data types
     • Real
       • Decimals, 12.6
     • String
       • Alphanumeric
     • Date/time
       • December'12
     • Boolean
       • Yes/No
     • Integer
       • Whole numbers

2. Data, information, knowledge and processing

   • Data
     • Unprocessed, raw facts and figures with no meaning
   • Information
     • Data+context+structure+meaning; it is processed data
   • Knowledge
     • The application of information to a situation
   • Processing
     • Performing an action on the data; sorting, searching or editing

3. Representation Methods

   • Text
     • Clear to understand ;lots of detail
     • Language barriers ;time consuming
   • Animation
     • Not language based and includes a lot of information
     • Problems if sound dependant/cant see and linear
   • LED
     • Secure data; good for noisy places
     • Directional and combinations must be known
   • Graphics
     • No language barriers
     • Confusing if symbols not understood
   • Sound
     • No sight required; no fixed position
     • Language barriers; can be distorted; hearing abilities

4. Quality of information and encoding

   • Age
   • Level of detail
   • Relevance
   • Accuracy
   • Completeness
   • Presentation
   • Encoding
     • Less memory required; higher level of security
     • Precision of data coarsened; codes need to be known to understand

5. Validation and Verification

   • Validation ensures data is reasonable, sensible and within boundaries of rules.
     • Range check
     • Check digit
     • Look up in list
     • Picture check
     • Presence check
     • Type check
     • Length Check
   • Verification ensures data is entered correctly
     • Errors
       • Transcription; it is miscopied
       • Transposition; numbers/letters are round the wrong way
     • Double entry
       • Compares 2 sets of manually entered data and informs user
       • If same mistake is made twice, it wont be picked up
     • Proof read
       • Paper copy compared with on screen copy
       • Difficult to transfer between paper and screen

6. Backup and Archiving

   • Archiving
     • Moving data which is needed in the long term or not immediately required into storage
   • Back Up
     • A copy of data and can be used to restore data. Stored on removable media and taken to another location

7. Input Processing Output Storage and Feedback

   • Input
     • Entering data into the system, manual or electronic
       • Ticket requested
   • Procesing
     • Action performed on the data
       • Search to find the tickets
   • Storage
     • Where the data is held
       • Details of request
   • Output
     • Outputting the input data
       • "No tickets"
   • Feedback
     • The output forms part of the input back into the system
       • Put on waiting list for more tickets

8. Costs of producing information

   • Software
     • Graphics, DTP
   • Consumables
     • Paper and ink
   • Personell
     • Wages and training
   • Hardware
     • Storage and maintainence