Question

Part 2 of 2 - Two-way ANOVA

Two-way ANOVA: For the problem below, use the ANOVA table to determine whether the main effects and interaction were significant. Use the table of means and effect sizes to interpret the significant effects.

Katy is interested in the impact of different types of studying methods on students’ memory for different topics. She assesses the impact of flashcards versus study guides on students’ memory of biology versus psychology. The mean performance memory scores, ANOVA table, and effect sizes are reported below.

Mean memory scores: (Higher score = better memory)

Flashcards

Study guides

Biology

12

10

Psychology

30

32

ANOVA table:

Source

SS

df

MS

F

Between

Studying method

15.23

1

15.23

2.53

Topic

37.11

1

37.11

6.16*

Interaction

16.17

1

12.17

2.68

Within

120.40

20

6.02

Total

188.91

23

*p < .05

Eta-squared (n2): Notetaking method = 0.03, Topic = 0.22, Interaction = 0.05

Question 6 of 8

Write yes or no. (2 pts. each)

Was there a significant main effect of studying method?

Was there a significant main effect of topic?   

Was there a significant interaction?

Mark for Review What's This?

Question 7 of 8

For the following statements, write true or false based on the results and STATISTICAL interpretation of the ANOVA analysis: (2 pts. each)

Overall, students remembered more in psychology than in biology.

Overall, students remembered more after flashcards than after study guides.   

Overall, studying method did not impact student memory.

Students remembered more after flashcards in biology and more after study guides in psychology.   

The impact of study guides on memory was dependent on the topic.   

Flashcards led to better memory regardless of topic.   

Students remembered more in psychology regardless of studying method.   

Mark for Review What's This?

Question 8 of 8

Which of the following had the greatest impact on variance in students’ memory?

A. Studying method

B. Topic

C. Interaction

Reset Selection

Answer 1

As shown below we calculate the pvalue for each the main effect and the interaction term.

If the pvalue is less than 0.05, we consider it to significant.

Was there a significant main effect of studying method?
No because the pvalue is greater than 0.05

Was there a significant main effect of topic?   
Yes because the pvalue is less than 0.05

Was there a significant interaction?
No because the pvalue is greater than 0.05

To answer the following question, we need to understand the hypothesis of the Anova and their results.

Hypothesis 1 : Studying method
Ho : The mean memory score for studying methods is equal .
H1 : The mean memory score for studying methods is not equal

Analysis: We see that the pvalue is greater than 0.05, hence we reject fail to reject the null hypothesis and conclude that mean memory score for studying methods is equal .

Hypothesis 2 : Topic
Ho : The mean memory score for topics is equal.
H1 : The mean memory score for topics is not equal

Analysis: We see that the pvalue is less than 0.05, hence we reject to reject the null hypothesis and conclude that mean memory score for topics is not equal

Hypothesis 3: Interaction
Ho: There is no interaction between the studying method and topic
H1: There is an interaction between the studying method and topic

Analysis: We see that the pvalue is greater than 0.05, hence we reject fail to reject the null hypothesis and conclude that there is no interaction between studying method and topic

True or False

Overall, students remembered more in psychology than in biology.
True, (Hypothesis 2 : since there is a significant difference in the mean memory score for the topics)

Overall, students remembered more after flashcards than after study guides.
False(Hypothesis 1 : since there is a no significant difference in the mean memory score for the studying method)

Overall, studying method did not impact student memory.
True(Hypothesis 1 : since there is a no significant difference in the mean memory score for the studying method)

Students remembered more after flashcards in biology and more after study guides in psychology.
False(Hypothesis 3 : since the interaction between topic and studying method is not significant)

The impact of study guides on memory was dependent on the topic.   
False(Hypothesis 3 : since the interaction between topic and studying method is not significant)

Flashcards led to better memory regardless of topic.
False(Hypothesis 1 : since there is a no significant difference in the mean memory score for the studying method)  

Students remembered more in psychology regardless of the studying method.   
True, (Hypothesis 2 : since there is a significant difference in the mean memory score for the topics)

Which of the following had the greatest impact on variance in students’ memory?
B. Topic