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This study investigates the impact of college major (psychology, sociology, biology) and gender (male, female) on class attendance. By utilizing simple effects analysis, we explore attendance variations among different majors and genders, specifically examining if female students’ attendance is influenced by their major and whether there are attendance differences between male and female psychology students. Multiple analyses, including ANOVAs and t-tests, are conducted to assess these relationships. The findings aim to enhance understanding of attendance patterns in higher education.
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Remember • You were asked to determine the effects of both college major (psychology, sociology, and biology) and gender (male and female) on class attendance
Simple Effects • The effect of one factor at one level on the other factor. • Use to “tease apart” a significant interaction • You wonder if college major has an effect on class attendance for just females? • You wonder if male and female psychology students differ in their class attendance?
Simple Effects • Why not just do 5 new analyses • 2 ANOVAs • 3 Independent Samples t-tests • You will lose df! • Type I error problem still exists
Simple Effects • SS Major at Female • Represents the SS deviations of the treatment means around the Female mean • Its multiplied by n to give an estimate of the population variance (Central limit theorem) • Same formula as SSbetween in the one-way
SS M at Female = 3*((2.67 – 1.78)2 + (1.00 – 1.78)2 + (1.67 – 1.78)2 = 4.23
Simple Effects • SS Major at Male • Same formula as SSbetween in the one-way
SS M at Male = 3*((3.67 – 2.33)2 + (3.00 – 2.33)2 + (0.33 – 2.33)2 = 18.71
Simple Effects • SS Gender at Socio • Same formula as SSbetween in the one-way
Simple Effects • SS Gender at Psych • Same formula as SSbetween in the one-way
Simple Effects • SS Gender at Bio • Same formula as SSbetween in the one-way
Simple Effects dfA (Gender) = a – 1 dfB (Major) = b – 1
Simple Effects Compute MS
Simple Effects Compute F
F critical (1, 12) = 4.75 F critical B (2, 12) = 3.89 Simple Effects
Practice • ANOVA is from exercise 13.5 • 1) Interpret the ANOVA results • 2) Plot the cell means • 3) Compute an entire set of simple effects