Topic 1: Data, Information & Knowledge

Topic 1: Data, Information & Knowledge

1. Encoding and the storage of data

   • Encoding
     • Assigning codes to the data reducing its size.
       • example : size of clothes- S= Small, M= Medium, L= Large
         • ad
           • takes up less storage space, easily transferable, easier to back
         • dis
           • Easily stolen, training needed, security problem, viruses
   • transcription error
     • Error made when typing in data using a document as the source of the data.
       • Example mishearing what a person says over the telephone and entering it into the computer.
   • Transposition error
     • Error made when characters are swapped around so they are in the wrong order.
       • Example would be putting faceboko instead of facebook
   • Check digit
     • A decimal number (or alphanumeric character) added to a number for the purpose of detecting the sorts of errors humans normally make on data entry.
       • Example account numbers will have check digits, to check that the numbers inputted are correct.
   • Range check
     • Data validation technique which checks that the data input to a computer is within a certain range.
       • Example would be checking the data of birth of a yr 9 pupil. If their date of birth is lower than 1998, the system wouldn’t allow that person to enter that date as they are too old for yr 9.

2. core

   • GIGO
     • garbage in garbage out
       • if you put rubbish into the computer then you get rubbish out.
   • data
     • Raw facts and figures with no meaning, e.g. readings from sensors and survey facts
       • Data can be numbers, words, images, sound
   • Processing
     • Data is processed by a computer. Performing calculations or arranging the data into a meaningful order.
       • Example would be working out an athlete’s average age over 3 years.
   • Information
     • Data that has been processed by the computer.
       • Data + Meaning + Context = Information
   • Knowledge
     • Derived from information by applying rules to it.
       • Knowledge is the application of information to a situation.

3. Data verification

   • Batch total
     • A meaningful total that is used to check that the computer has input all the data.
       • For example adding up all the totals of a batch of sold ebay items.
   • Hash total
     • Meaningless total of numbers, such as order numbers, used to check that all the data has been entered.
   • Parity check
     • Check to make sure that the data sent is the same as that received when data is transmitted from one computer to another
       • An example would be an email sent from one person to another.
   • Verification
     • Checking that the data being entered into the ICT system perfectly matches the source of the data.
       • An example would be checking the text/ data in an email and making sure when it arrives to the recipient that no error have been introduced.