Chapter 1

Chapter 1

1. Data Types

   • Data = Raw facts and figures that have no meaning.
   • Structure = How the data is presented.
   • Context = An environment where our prior knowledge and understanding can make sense of the data.
   • Meaning = Data with the correct structure and placed within the context.
   • Knowledge is the APPLICATION of INFORMATION to a SITUATION e.g. putting that information to use
   • Boolean
     • Only have one of two values (either True or False, or Yes or No
   • Real
     • Decimal places
   • Integer
     • Whole numbers
   • String
     • A list of letters, symbols, characters and/or numbers
   • Date/Time
     • Stores date and time values.

2. Different types of methods to convey meaning.

   • Text
     • e.g. Instructions
     • Advantages
       • Explanations can be given
     • Disadvantages
       • Blind people can’t read text and anybody with dyslexia will have difficulties reading.
   • Pictures
     • e.g. Screenshot
     • Advantages
       • There are no language barriers with images
     • Disadvantages
       • Images on their own cannot give explanations or instructions.
   • Sound
     • e.g. Ringtone
     • Advantages
       • Sound can be used to grab people’s attention
     • Disadvantages
       • Deaf people cannot hear what is being said or what noise is being made
   • Videos
     • e.g. YouTube
     • Advantages
       • Videos can include both sound and video
     • Disadvantages
       • Videos require a display screen and speakers to be viewed and heard.
   • Animation
     • e.g. Images used to create an animation
     • Advantages
       • Animations are not dependent upon a person understanding a specific language.
     • Disadvantages
       • Animation does not include sound.
   • LED
     • e.g. Clocks
     • Advantages
       • LEDs use up very little power and are cheap to produce.
     • Disadvantages
       • LEDs on their own do not mean anything and so text or images are also needed to show what the lights indicate.

3. Sources of Data

   • Direct
     • If data is used for same purpose it was originally collected for
   • Indirect
     • If data is used for a different purpose to that it was originally collected for

4. Static and Dynamic Data

   • Dynamic
     • Dynamic data can change
   • Static
     • Static data does not change

5. How does the following affect the quality of the information produced?

   • Accuracey
     • Accurate data must be correct.
   • Relevance
     • Information must be relevant for the purpose it is being used
   • Age
     • The data must be up-to-date for the purpose it is being used
   • Completeness
     • It is important that all the data required is available
   • Presentation
     • If data ispresented badly meaning that it is difficult to interpret or too confusing to understand
   • Level of Data
     • The level of detail within information is a combination of relevance and completeness

6. Encoding Methods

   • Numerical Representations
     • This is when words or descriptions are replaced by numbers.
   • Abbreviations
     • This involves replacing words or descriptions with letters that are related to those words or descriptions
   • Value Judgements
     • These are used in questionnaires when a respondent is asked what they think about a particular thing.

7. Validation Methods

   • Presence Check
     • Ensures that some data has been entered for a particular field
   • Length Check
     • Ensures that data is a minimum, maximum or specific length
   • Type Check
     • Checks to see that the data is the correct data type

8. Verification Methods

   • Double Entry
     • Asks for the data to be entered twice
       • e.g. When creating a password
   • Proof Reading/Manual Verification
     • visually checking that the data entered on the computer matches the original source data.

9. Backing up and Archiving Data

   • Backing up
     • A backup of data is a copy of data.
     • Backups of data can be made to many different types of media.
       • Tape
       • Re-writeable optical memory
       • Flash memory (USB storage pen)
       • On-line storage
   • Archiving
     • Involves moving the data rather than copying it
     • When files are archived, they are moved from immediate access to another storage medium

10. Costs of Producing Information

    • Hardware
      • Any equipment that is required to collect or produce information
        • Speakers
        • Camera
        • Computer
    • Software
      • software is likely to be purchased once and used many times for the collection and processing of data
        • Desktop Publishing
        • Spreadsheet
        • Video Editing
    • Consumables
      • Something that is used up and can not be used again.
        • Paper
        • Ink
    • Personnel
      • People are needed to collect and produce information
        • Training
        • Graphic Designer

11. Information Processors

    • Input
      • Data that is put in to the computer system
      • It can be as simple as letters, numbers and symbols being typed onto a keyboard or complex like video with moving images and sound
    • Processing
      • Once the data has been received by the computer system, the processor will need to process the data
      • The processor will manipulate the data by performing calculations or sorting the data or transforming it in some other way before it is ready to be stored or output.
    • Output
      • Once data has been processed, it is transformed into information which can be put out of the computer system
    • Storage
      • Data can be stored in two forms
        • temporarily while processing is taking place (eg using RAM)
        • longer term storage on secondary storage devices (eg hard disk)