1. Describe the circumstances under which you should use ANOVA instead of t tests, and explain why t tests are inappropriate in these circumstances.

2. The following data were collected from a repeatedmeasures study. F is calculated as 8.10

Determine if there are any significant differences among the four treatments. Use

the.05 level of significance.

Treatments

Participant A B C D

_________________________________________

1 6 3 3 0

2 4 4 2 2

3 4 2 0 2

4 10 7 7 4

_________________________________________

3. The results from a two-factor experiment can be presented in a matrix with the levels of one factor forming the rows and the levels of the second factor forming the columns, with a separate sample in each of the matrix cells. Using this matrix structure, describe what is meant by the "main effect" for each factor and the "interaction" between factors.

4. Enter the following data (an experimental study with three treatment groups; each group consists of five scores) into SPSS and conduct an ONEWAY ANOVA in SPSS to determine whether there are significant differences among the three treatments. Request (a) Tukey post-hoc test in the post hoc box, and (b) in the options box request descriptives. (General instructions for using SPSS are presented in Appendix D. SPSS instructions for One-way ANOVA is on p. 424 of 9^thedition)

Treatment I

Treatment I

Treatment I

0 2 2 0 1

4 6 1 5 4

1 0 3 1 0

a. Is the overall F-ratio significant? At which p-level?

b. What is the decision?