Graphical Representations

• Bar charts:

  • Display discrete/categorical data
  • Used when data is divided into categories, these appear as words rather than numbers
  • Categories occupy the horizontal x axis
  • Amount is plotted on the vertical y axis
  • Used to compare conditions
  • The bars never touch to show that the conditions are separate

  
• Histograms:

  • Display continuous data or data where each participant has an individual score
  • Represent frequencies
  • Scores which are made of equal sized intervals will be represented on the horizontal x axis, creates equal width in bars
  • Frequency will be represented on the vertical y axis
  • Bars should always touch, and the vertical y axis shows the data is continuous

  
• Scatterplot:

  • Used to display a relationship between two co-variables
  • Represents correlations
  • Each plot on the graph represents one participant but two scores (one for each co-variable)
  • One co-variable goes along the horizontal x axis and the other goes along the vertical y axis