Presenting Data

• What are bar charts used for?

  Presenting categorical or discrete data
• When should bar charts be used?

  When the independent variable is categorical or discrete
• What type of scale is used in bar charts?

  Linear scale
• What does discrete data represent?

  Values with no in-between values
• What is the purpose of a key in a bar chart?

  To differentiate multiple data sets
• What is plotted on the y-axis of a graph?

  Dependent variable
• What does the gradient of a graph indicate?

  How quickly the dependent variable changes
• What type of data can continuous data take?

  Any numerical value within a range
• How is the gradient calculated?

  $\text{Gradient} =$$\frac{\text{change in } y}{\text{change in } x}$
• What are the three types of correlation between variables?

  • Positive correlation
  • Inverse (negative) correlation
  • No correlation
• What is a line of best fit used for?

  To summarize the trend in data points
• What is an anomalous result?

  A data point that deviates from others
• What should be marked with a small, neat cross on a graph?

  Anomalous results
• What is a sensible scale on axes important for?

  To accurately represent the data
• What is a possible reason for a correlation?

  Chance correlation might be a fluke
• What does a third variable imply in correlation?

  Another factor links the two variables
• What can be concluded if every other variable is controlled?

  Changing one variable causes change in another