next up previous contents index
Next: Symmetry and Skewness Up: Summarizing Numerical Data Previous: Box-and-Whisker Plot

Dotplot

For moderately large samples, a dotplot  diagram is also an effective method of examining the shape of the distribution. We present dotplots of HS GPA and 2nd year GPA below. Note the much longer left tail of 2nd year GPA which was apparent from the comparison boxplots shown earlier. Also note the extremely low outlier for 2nd year GPA.



      Comparison Dotplots: High School GPA versus 2nd Year College GPA

                                       .  .
                                       :  :       .  .
                                       : .: .   . :  :  .
                                    .:.::::.: .::::..:.::: .
       -----+---------+---------+---------+---------+---------+-HS GPA  
                                             :
                                 :       . :::.
         .         ...     :: ...:..:.:..:.:::: :..::.. .
       -----+---------+---------+---------+---------+---------+-GPA2    
         0.70      1.40      2.10      2.80      3.50      4.20






2003-09-08