ICT GCSE - Topic 1 : Data, Information, Knowledge

ICT GCSE - Topic 1 : Data, Information, Knowledge

1. Evaluating data for fitness for purpose, accuracy and bias

   • GIGO
     • Abbreviation for garbage in garbage out. It means if you out rubbish in the computer - then you get rubbish out.
   • Data
     • Raw facts and figures with no meaning, e.g. readings from sensors and survey facts, etc. Data can be numbers, words, images, sound.
   • Processing
     • Data is processed by a computer. Performing calculations or arranging the data into a meaningful order. Eg. Working out an athlete's average age over 3 tears.
   • Information
     • Data that has been 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.
   • Example -
     • 99 = Data, £99 price of tv = information, I only have £90 therefore I do not have enough money to buy this tv

2. Encoding and the storage of data

   • Encoding
     • Assigning codes to the data, reducing it's size.
       • E.g - Size of clothes - S = Small, M = Medium, L = Large.
       • E.g - Airport codes - LHR = London Heathrow, MAN = Manchester.
     • Advantages
       • Takes up less storage space, easily transferable, easier to back.
     • Disadvantages
       • Easily stolen, training needed, security problems, viruses etc.

3. Data Validation

   • Transcription error
     • Error made when typing in data using a document as the source of the data. E.g - Mishearing what a person says over the phone and entering it into the computer.
     • Presence Check
       • Is used to check that data is entered is entered into the correct fields. E.g - Entering your username and password into facebook.
   • Transposition error
     • Error made when characters are swapped around so they are in the wrong order. E.g - putting in faceboko instead of facebook
     • validation Checks
       • Are checks a developer of a solution sets/ creates, using the software, in order to restrict the data that a user can enter, so as to reduce errors. Presence and range checks are validation check examples.
   • Check digit
     • A decimal number (or an alphanumeric character) added to a number for the purpose of detecting the sorts of errors that humans normally make on a data entry. E.g - 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. E.g - checking the data of birth of a year 9 pupil is lower than 1998, since the system wouldn't allow that person to enter that date as they are too old for year 9.

4. Data verification

   • Batch total
     • A meaningful total that is used to check that the computer has input all the data. E.g - adding up all the totals of a batch of sold ebay items.
   • Hatch 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 recieved when data is transmitted from one computer to another. E.g - 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. E.g - Checking the text/ data in an email and making sure when it arrives to the recipient that no error has been introduced.