Displaying Univariate Data
 
 
 

Graphical techniques for:
 

  • nominal data

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  • ordinal data

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  • interval data

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    More on graphical techniques
     

  • bar chart
  • gaps should be constant
  • order of bars meaningless for nominal variables; order for ordinal variables


    • Additional techniques for interval variables
     
     

  • dotplot - one dot for each observation on a numbered axis
  • histogram - varying widths of class intervals

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  • outliers - observations that are extreme relative to rest of distribution

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    Additional principle for statistical graphics:

    use the simplest display possible - no unnecessary clutter, special effects!