10_PSY 305 Assignment 3

Instructions- Calculate this ANOVA by hand.  Check your work by also calculating the ANOVA in SPSS or EXCEL.  Be sure to do any multiple comparison tests and interpret the results.

Control GroupA1

PsychoanalysisA2

CBTA3

X1

7

7

3

X2

10

5

3

X3

6

6

2

X4

8

5

3

X5

10

5

4

X6

10

6

2

X barA1

SX (A1)

SX²

SST = SX² – T²/an                             (also called [X] – [T])

SST =                                                  (a = number of groups, n = number in each group)

SST =

SSA = SA²-   T²                                 (also called  [A] – [T])

             n        an

SSA =

SSA =

SSS/A = SX² - SA²                                        (also called [Y] – [A] )

                         N

SSS/A = 

Now divide by its df to change it to variance.  Variance is called Mean Square.

Complete ANOVA summary table on next page.

ANOVA Summary Table

Source                                   SS                   df                     MS                  F

A-group                     

S/A (error)                 

Total                                      

Find F-critical.

Are the groups significantly different?

Write the results statistically.

What do you do next?  Why?

Which groups are different?