Within vs Between Subjects

• Explain the difference between a within subjects variable and a between subjects variable.

• Recognize examples of within and between subjects variables.

• Explain the advantages and disadvantages of each type of variable.

• Explain when each type of variable can or cannot be used, should or should not be used, and the consequences of the choice.

• Explain the significance of the number of levels of factors for between and within subjects designs.

• Describe experimental designs which use both within and between subjects variables.
  • Distinguish between number of subjects and number of observations.
  • Explain the consequences for the number of subjects needed and for power
  • Read an anova table and reconstruct the design by examining the error terms and the degrees of freedom.

• Organize data from between subjects, within subjects, and combined designs for analysis.

• Use a statistical analysis program, such as SPSS, to analyze between subjects designs, within subjects designs, and designs with both kinds of factors.