STEM topics test 2

• Data: information and facts that are collected together
• Data types=

  Quantitative discrete: whole numbers

  Quantitative continuous: not whole numbers

  Qualitative ordinal: words that can be put in an order

  Qualitative nominal: words that can't be ordered
• Data is important to: help us to make decisions or to understand a topic
• Data is only useful if it is sorted and organised
• Spreadsheets allow us to record and store data.
• Vertical = to the sky

  Horizontal = on the ground
• Formulas for additon:

  =SUM(D2,A3)

  =SUM(A2:D2)
• Graphs are easier to read than spread sheets and make it easier to see trends or changes in the data
• Binary is a number system that is made up of 0's and 1's. These 0's and 1's can make up any number to create larger numbers
• Binary: 8 numbers ( doubled each time)
• Every character on your keyboard can become a number
• ASCII uses 7 bits which can make 127 different numbers for letters, numbers, symbols and commands.
• ASCII can not represent all languages so we use Unicode. Unicode can use more bits so can represent everything else.
• Sorting data: arranging data into a better order tk make it easier to read and understand

  Cleaning data: removing irrelevant or incorrect data

  Interpreting data: using data to.make a decision.
• Formulas:

  =AVERAGE(cell:cell)

  =SUM(cell:cell)

  =MODE (cell:cell)

  =MEDIAN(cell:cell)

  =MAX(cell:cell)

  =MIN(cell:cell)
• Primary data


  Data collected by a person conducting an investigation
• Secondary data


  Data collected from a source where they have already conducted an investigation
• Data can be collected through primary and secondary methods
• Big data


  "Extremely large datasets that may be analysed computationally to reveal patterns, trends, and associations, especially relating to human behaviour and interactions." (Oxford Language Dictionary)
• Database

  "A database is an organised collection of structured information, or data, typically stored electronically in a computer system. A database is usually controlled by a database management system (DBMS)." (Oracle Australia)
• Pixels


  The smallest unit in a digital display. Pixels make up images and videos on a devices screen.
• Subpixels


  Every pixel contains a subpixel that can emit red, green, or blue light (RGB)
• RGB


  • Red
  • Green
  • Blue
• RGB is always represented in this order
• RGB values

  • RGB (255, 0, 0) implies a red pixel
  • RGB (0, 255, 0) implies a green pixel
  • RGB (0, 0, 255) implies a blue pixel
  • RGB (255, 255, 255) is a white pixel
  • RGB (0, 0, 0) is a black pixel
• Audio files convert analog audio into its digital form
• Computers are an electronic device that manipulate information or data. They are made up of hardware and software.
• Software: computers operating system (OS), applications and security programs

  Eg. Microsoft Excel
• Hardware: physical parts of a computer

  Eg. Keyboard, CPU, Ram
• Input: information we enter into a computer

  Examples: mouse, keyboard, microphone, game controller
• Output: information or results that the computer sends back to us

  Examples: monitor, Headphones, printer
• an integer is any whole number including positives, negatives and 0.
• Graph data is information that is shown as a visual image or picture.
• Bit: short for binary digit. It is the smallest unit of data in a computer. It has a single binary value of 1 or 0.
• Byte: a byte is made up of 8 bits. It is a unit of data that is 8 binary digits long
• Not all images are made from pixels. Vector graphics are made up if lines, curves and shapes. Each part of a vector graphic is called an object. These images are easily editable.
• Computers will always:

  1. Input
  2. Storage
  3. Processing
  4. Output
• A digital system is a group of different hardware and software peices that work together to organise, process, collect and store data.
• An information system is a set of different peices used to collect, process and store data. Information systems create a digital solution and problem to a task.