CASE STUDY

Dr. Antonia Natalie, Professor of Psychology at Thoreau University, wants to determine if her optional weekly Zoom lectures are having an impact on students’ grades in a graduate-level Behavioral Statistics course.

During the semester the professor records attendance for each of her ten Zoom lectures. Based on student attendance the professor creates 3 equal student groups. Group 1 (n = 50) consists of students that did not attend any Zoom Lectures. Group 2 (n = 50) consists of students that attended one to five lectures. And Group 3 (n = 50) consists of students that attended six to ten Zoom lectures.

Concerned that students that attend more Zoom lectures may also have higher Quantitative Reasoning Skills, the professor also records GRE Quantitative scores (GRE-Q) for each student.

Your job is to conduct an ANCOVA to determine if the Zoom attendance groups have significantly different final grade averages (on a 100-point scale ) in the Behavioral Statistics course, after controlling for their GRE-Q scores.

Conduct a Oneway ANOVA to determine if the three groups differ significantly on the GRE-Q measure. Report and summarize the results in correct APA style. What conclusions can you draw from these results? And do the three groups differ significantly in quantitative reasoning skills – if so, how? Is it justified to use GRE-Q as a covariate, Why?

Using the attached SPSS Data file, conduct the appropriate preliminary EDA to determine if a) the data meets the assumptions for ANCOVA (i.e., test for skewness/kurtosis), b) test for homogeneity of regression, and c) test for homogeneity of variances.

Conduct an ANCOVA in which Statistics grades (StatGrade) is the DV, Zoom group (ZGroup) is the IV, and GRE_Q is the covariate (CV). If the main effect for ZGroup is significant, conduct Bonferroni’s post hoc mean comparison tests.

In your summary:

1: State the goals of the present study

2: Write the correct Null (H0) and Alternative (H1) hypotheses

3: Report the results for the Oneway ANOVA in which Zgroup is the IV and GRE-Q is the DV.

4: Report and summarize the results for the tests for normality, homogeneity of regression slopes, and homogeneity of variances.

5: Report and summarize the results for the ANCOVA and post hoc mean comparison tests.

6: Be sure to include in your summary the conclusions and recommendation that can be drawn from the study.

7: Be sure to include the appropriate tables and figures. See my sample summary.

8: Model your summary after my sample summary.