22-11-2012, 05:24 PM
ANOVA and Multiple Comparisons in SPSS
ANOVA and Multiple.pdf (Size: 293.38 KB / Downloads: 1,064)
Three sets of five mice were randomly selected to be placed in a standard maze but with different color
doors. The response is the time required to complete the maze as seen below. Perform the appropriate
analysis to test if there is an effect due to door color. (Use α = 0.01)
1. Enter the group number (1 for Red, 2 for Green, 3 for Black) into one variable and the
corresponding time values into another variable (see upper-right figure, below). Be sure to code
your variables appropriately. Now it is time to check the normality assumption. Select “Split
File” from the “Data” menu so that we can tell SPSS that we want separate Q–Q Plots for each
group (see upper-right figure, below). Select “Organize output by groups” and enter “color” as
the variable that groups are based upon (see lower-left figure, below). Now create Normal Q–Q
Plots to assess the normality of each group (see separate handout on Normal Q–Q Plots). Once
you’ve created your Q–Q Plots and determined that your groups are approximately normally
distributed, select “Split File” from the “Data” menu and then select “Analyze all cases, do not
create groups” in order to return SPSS to its normal data analysis mode (see lower-right figure,
below).