Explain the following terms:

-ANOVA

-One-way design

-Between subjects

-Within subjects

-Two-way design

A researcher conducts two studies. Study One uses a one-way between-subjects ANOVA, and Study Two uses a within-subjects ANOVA. If the number of groups and participants per group are the same in each study, then in which study was the total number of participants larger? Explain your answer.

When is it necessary to perform post hoc comparisons?

Why do we perform post hoc tests?

In a two-way ANOVA: For a 2x2 ANOVA, describe in words the statistical hypothesis

for Factor A, Factor B, and AxB.

The following is an incomplete One-Way ANOVA table summarizing the results of a

study of the variance of life satisfaction scores among unemployed, retired, part-time, and full-time employees. Complete the F table and make a decision to reject or fail to reject the null hypothesis.

We compare the final exam grades of students taking statistics in the morning (mean = 76.2), in the afternoon (mean = 74.45), and in the evening (mean = 72.53). With n = 10 we compute the following sums of squares:

a. Complete the ANOVA table b. What is Fcrit?

Source	SS	df	MS	F
Between Groups			16
Within Groups		36
Total	128

Source	SS	df	MS	F
Between Groups	127.60
Within Groups	693.45
Total	821.05

1

Psy07301 Fall 2022 Diorio Homework Unit 4

c. Is there a significant difference between the class means? d. What other procedures should be performed? e. Based on these results, what psychological explanation can you give for why the time of day the class meets has no influence on grades?

What's the difference between a one-way ANOVA and a two-way ANOVA?

A researcher conducts a 3x3 between-subjects ANOVA with 15 participants assigned to each group.

What is the total sample size in this study?

How many groups are in the study?

Joanne examined eye-hand coordination scores for three levels of reward and three levels of practice. She obtained the means given below:

Reward

Low Medium High

4	10	7	7
5	5	14	8
15	15	15	15
8	10	12

Practice Low Medium

High

a. What are the main effect means for reward, and if Fobt is significant, what do they appear to indicate? b. What are the main effect means for practice, and if Fobt is significant, what do they appear to indicate?

c. What procedure should be performed to confirm your answers to part a and b? d. What else has she forgotten to examine?

11. Students at a local college (freshman, sophomores, juniors, seniors) who were in the same statistics class were given one of three tests (recall, recognition, or a mix of both). Test grades for each participant (n = 10) were recorded. Complete the F table for this study.

Source	SS	df	MS	F
Exam (A)		2	95
Student Class (B)	60
Exam x Student Class (AxB)	540
Within Groups
Total	2410

2

Psy07301 Fall 2022 Diorio Homework Unit 4

12. Assume the following data for a study:

M1 = 146.98, n = 21 M2 = 140.45, n = 21 M3 = 147.04, n = 21 M4 = 142.66, n = 21

Conduct a Tukey HSD on the ANOVA at alpha = .01. Between which pair(s) doe the statistical significance lie?

Source	SS	df	MS	F
Between	642.84	3	214.28	5.12
Within	3346.52	80	41.83
Total	3989.36	83