Instructions: This is a three part assignment in which you will demonstrate your ability to: Compute and

Instructions:

This is a three part assignment in which you will demonstrate your ability to:

Compute and interpret a post-hoc power analysis.
Compute and interpret an a priori power analysis.
Predict and confirm your prediction with a statistical analysis.

A prediction prior to analysis:
- Prior to doing the power analysis, click on the Table for Data Analysis and Application . You will use this table to create an SPSS data file and name it u02a1.sav . Then use SPSS to survey the means and standard deviations of ADDSC scores in each gender group.

Assume the standard deviation for both groups is 12. Would you expect a large, medium, or small effect when examining the differences between genders on ADDSC? Why?

Post hoc analysis:

Compute the effect size with gender as the grouping variable and ADDSC as the dependent variable.
Compute delta.
Compute power using a .05 alpha and a two-tailed test. When you are using G*Power, make sure you have selected the independent t-test and the two-tailed option.
Interpret the meaning of the three values you just calculated.

A priori analysis:

Assume the effect size that you calculated above in part 1. How many total subjects (N) would be needed to obtain a power of .90?
Would you have expected a required N of this size? Why or why not? Interpret the meaning of a .90 power value. Note that G*Power will provide the combined N (the N for both groups).

A prediction and analysis:

Suppose you now wanted to determine whether there was a significant difference between the means for the women versus the men. Reviewing the descriptive information and the calculated power value in Part II, would you expect there to be a significant difference between the means? Why or why not?
Using the appropriate statistical procedure on the SPSS, test the between group means for a significant difference. Report the SPSS results and your conclusion.

Price: $13.12

Solution: The downloadable solution consists of 8 pages, 512 words and 4 charts.
Deliverable: Word Document