Chapter 11 Factorial ANOVA Factorial ANOVA Example
Chapter 11 Factorial ANOVA
Factorial ANOVA Example
Design Independent variables: • Sex (2 levels) • Group (4 levels) • • • •
Pedometer only Pedometer and written support Pedometer and personal support Pedometer, personal and computer support
Dependent variable: • Steps taken/week N = 50 in each Group (25 males, 25 females) Factorial ANOVA • 2 X 4 Between-Between design
SPSS Variable View
SPSS Results Check to see that the data were entered correctly
Descriptive Statistics Descriptive statistics for each of the eight cells
Main Effect for Sex F-test for Sex is not significant
Main Effect for Groups F-test for Group is significant
Main Effect for Interaction F-test for Interaction is not significant
Examination of Interaction Effect
Although the two lines indicating the pattern of the steps taken per week by the four groups are not identical for males and females they are not different enough to result in a significant interaction.
Examination of Group Effect
Using the SNK multiple comparison technique we determine: Pedometer Group does not differ from Pedometer & Written Support Group Pedometer & Written Support Group does not differ from Pedometer & Personal Support Group Pedometer Group differs from Pedometer & Personal Support Group Pedometer, Personal, & Computer Support Group differs from all other three Groups
Factorial ANOVA Example
Design Independent variables: • Sex (2 levels) • Group (4 levels) • • • •
Pedometer only Pedometer and written support Pedometer and personal support Pedometer, personal and computer support
Dependent variable: • Steps taken/week N = 50 in each Group (25 males, 25 females) Factorial ANOVA • 2 X 4 Between-Between design
SPSS Variable View
SPSS Results Check to see that the data were entered correctly
Descriptive Statistics Descriptive statistics for each of the eight cells
Main Effect for Sex F-test for Sex is not significant
Main Effect for Groups F-test for Group is significant
Main Effect for Interaction F-test for Interaction is not significant
Examination of Interaction Effect
Although the two lines indicating the pattern of the steps taken per week by the four groups are not identical for males and females they are not different enough to result in a significant interaction.
Examination of Group Effect
Using the SNK multiple comparison technique we determine: Pedometer Group does not differ from Pedometer & Written Support Group Pedometer & Written Support Group does not differ from Pedometer & Personal Support Group Pedometer Group differs from Pedometer & Personal Support Group Pedometer, Personal, & Computer Support Group differs from all other three Groups
