What are the two IVs you selected? Do your IVs represent a fixed, random, or mixed effects model? What are the one DV and one CV you selected? How did you determine the CV?
This assignment allows you to perform a factorial analysis of covariance (ANCOVA) using SPSS. You will have an opportunity to explore the robustness of Statistical Package for the Social Sciences (SPSS) as a tool for performing this analysis and to appreciate both the process and the outcomes of this statistical analysis. This exercise serves as a prelude to multivariate analysis of variance (MANOVA)/covariance (MANCOVA).
Open the SPSS data file (.sav) you created from Database A for assignments.xls in M2: Assignment 1. Then, conduct an ANCOVA by completing the following tasks:
- Considering what might be a possible research question and hypotheses for outcomes from the variables in the data set provided, select/create appropriate categorical variables to serve as follows:
- Two independent variables (IVs)
- One continuous dependent variable (DV)
- One continuous covariate (CV) for a factorial ANCOVA
The IVs may include manipulation and/or subject/group variables.
Hint: Your selection of a covariate should depend on either a theoretical or observed significant correlation between the DV and the CV.
- Prescreen data and report results of prescreens (and any necessary transformations or other decisions) for the following:
- Missing data
- Homogeneity of variances
- Homogeneity of regression slopes
- Factor interaction
- Create BOX-WHISKER plots to visually examine assumptions for comparing groups.
- Conduct a two-way ANCOVA with post hoc tests if it is suggested by outcome of the main statistical analysis.
Save the SPSS file as R7034_M3_A1_LastName_FirstInitial.sav.
Write a two- to three-page response paper in Microsoft Word document format which provides the following information:
- What are the two IVs you selected? Do your IVs represent a fixed, random, or mixed effects model? What are the one DV and one CV you selected? How did you determine the CV?
- State a research question that could be studied using the selected variables and your hypotheses for main effects and/or interaction.
- Describe the results of your data screening.
- Present the results of the ANCOVA summary table, as well as the adjusted and unadjusted group means.
- Write a statement summarizing results in relation to the research question and the hypotheses.