Descriptive Statistics Module Map | |
|
Purpose To describe the common measures of central tendency and variability and demonstrate their use in summarizing a data set. Summary The module explains researchers' methods of producing a distribution of scores and illustrates the conceptual advantages of presenting these scores as a histogram or frequency polygon. Skewed and normal distributions are described and illustrated. Next the module explains and contrasts the measures of central tendency: mode, median, and mean. Measures of variability range and standard deviation are also explained. To review these concepts, the student creates a small distribution of scores, and the computer calculates the descriptive statistics for that distribution. Finally, the student has the opportunity to alter the scores in a distribution one at a time, to see the effect on the descriptive statistics for that distribution. |
|
|
Introduction Purpose of this module Distributions of scores Frequency histogram Frequency polygon Skewed distributions Symmetrical distributions Measures of central tendency The mode Problems with the mode The median The mean The problem of extreme scores |
Measures of variability The range The standard deviation Creating a distribution Summary References |
|
Click here to open the worksheet that accompanies this module. (Requires Adobe Acrobat Reader. Click here to get Adobe Acrobat Reader. Internet connection required to download plug-in.) | |