Assignment 1 Descriptive Statistics (due 2/4/15-2/9/15) (13. 5 pts)

3. Graph: Click Graphs on the tool bar (Legacy Dialogs if you have SPSS 15 or higher), select Bar, select “Simple” and “summaries for groups of cases,” click Define, select “other statistic (e.g., means),” move your DV into the first box and you’re your IV into the second box (says “Category Axis”). Click OK.

ONE-WAY ANOVA WORKSHEET

G =

k =

SS₁ =

n₁ =

M₁ =

T₂ =

SS₂ =

n₂ =

M₂ =

T₃ =

SS₃ =

n₃ =

M₃ =

T₄ =

SS₄ =

n₄ =

M₄ =

H_o: ₁ = ₂ = ₃ = ₄

H_A: All means are not equal
Between
Within
Total

 =

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

Your name ____________________________

Bonus Questions (5 pts)

The Relationship Between ANOVA and t-tests (5/15/15 - 5/18/15)

We probably do not have time to cover this topic in class. So I will give you an opportunity to earn extra points (p. 420-421). But this topic is really interesting!!.

When you have two samples, you can use either t test or ANOVA. It doesn’t matter which one you choose. Actually there is a relationship between t-test with independent samples and one way ANOVA. The relationship is F = t² . I want you to see this relationship.

You need the data from Assignment 7 (t-test with two independent samples).

1. 
   Looking at your SPSS output from Assignment 7, what is the t value you obtained? (1)
   

2. 
   Use SPSS to perform a one-way ANOVA. What F value did you obtain (attach your
   

3. 
   Square the t value you obtained above. Is the squared t value the same as the F value you obtained (except rounding error)? Now do you see the relationship between t² and F? This relationship holds true only when you have two samples. Now, you have learned something new. Aren’t you excited about this? (1)
   

Your name ____________________________

(Worksheet will be handed in class)

1. 
   Classify each scenario below in terms of the number of factors and the number of levels each factor has. For example, classify each scenario as a 2 x 3 design, or a 2 x 3 x 5 design, or some other variation. Identify factors as well.
   

1. 
   Men and women who are right-handed or left-handed and who use razors with blades versus electric razors are compared in terms of satisfaction with the smoothness of their shaves (1).
   

2. 
   Male and female students studying for traditionally female careers (e.g., nursing) or for traditionally male careers (e.g., engineering) are compared in terms of how androgynous they are (1).
   

2. 
   A developmental psychologist administered an aggression scale to a random sample of 50 boys and 50 girls. Hal of each sex had their level of physical aggression measured (getting into fights, throwing sticks and stones, etc.) and half had verbal aggression measured (spreading rumors, telling lies, etc.) On each scale, a higher score means more aggression.
   

1. 
   Graph the cell means (2).
   

2. 
   Which two means are compared to describe the main effect of aggression? (.5)
   

3. 
   Which two means are compared to describe the main effect of gender? (.5)
   

4. 
   Is there an interaction between sex and type of aggression? Explain your answer (.5).
   

3. 
   The following matrix presents the results from an independent-measures, two-factor study with a sample of n = 10 participants in each treatment condition. Note that one treatment mean is missing (1.5)
   

1. 
   What value for the missing mean would result in no main effect for Factor A?
   

2. 
   What value for the missing mean would result in no main effect for Factor B?
   

3. 
   What value for the missing mean would result in no interaction?
   

4. 
   A researcher conducts an independent-measures, two factor study with two levels of factor A and three levels of factor B, using a separate sample of n = 12 participants in each treatment condition (1.5).
   

1. 
   What are the df values for the F-ratio evaluating the main effect of Factor A? (remember you also need df_within)
   

2. 
   What are the df values for the F-ratio evaluating the main effect of factor B?
   

3. 
   What are the df values for the F-ratio evaluating the interaction?
   

5. 
   The following table summarizes the results from a 2 levels of Factor A and 3 levels of Factor B using a separate sample of n = 8 participants in each condition. Fill in the missing values (Hint: Start with the df values). Indicate whether each effect is significant by placing * next to your F value (3).
   

6. 
   Mathematics word problems can be particularly difficult, especially for primary-grade children. A recent study investigated a combination of techniques for teaching students to master these problems (Fuchs, Fuchs, Craddock, Hollenbeck, Hamlett, & Schatschneider, 2008). The study investigated the effectiveness of small-group tutoring and the effectiveness of a classroom instructional technique. A “hot-math” program teachers students to recognize types or categories of problems so that they can generalize skills from one problem to another. The following data are similar to the results obtained in the study. Scores below are math test scores.
   

b. State your hypotheses in statistical forms. State you hypothesis pertaining to an interaction effect in words. (3)

c. Conduct a two-way ANOVA by hand (use the worksheet) (10)

d. If the interaction effect is significant, using  = .01, conduct tests of either simple effects of the classroom instructional technique at each level of tutoring or simple effects of tutoring at each level of the classroom instructional technique (5).

e. Compute partial eta squared (η²) for each effect by hand (3).

6. 
   Use SPSS to (3)
   

2) Perform a two-way ANOVA.

3) Compute the cell means and standard deviations for each condition.

4) Create a bar graph. Be sure that the graph is neat and has all the necessary

information (label).

g. Annotate the printout, highlighting all the relevant results (1).

h. Write a results section in APA format (please use a word processor). Present the information in the following order. (5)

1) State that you used a .05 alpha level for all statistical tests.

2) Draw the reader’s attention to your bar graph (i.e., Figure shows or As can be seen in Figure …)

3) Describe the results of the tests. If there are significant differences in the tests of simple main effects, be sure to indicate the direction of the differences.

4) Interpret results and come up with a recommendation.

i. Staple the pages together in the following order: results section, figure, print out, and hand calculations.