In this assessment, you’ll begin to explore mean group differences in your courseroom data. Is it possible that being in a particular group results in higher or lower mean achievement levels? You’re going to explore possible differences in final exam scores for students who attended a review session versus students who did not attend a review session.
For this assessment:
Use the Data Analysis and Application template (DAA Template [DOCX] Download DAA Template [DOCX]).
For help with the statistical software, refer to the JASP Step-by-Step: t Tests [PDF] Download JASP Step-by-Step: t Tests [PDF]document.
View JASP Speedrun: t Test [Video] for a brief tutorial video on this assessment.
For information on the data set, refer to the 7864 Data Set Instructions [PDF] Download 7864 Data Set Instructions [PDF]document.
The grades.jasp Download grades.jaspfile is a sample data set. The data represent a teacher’s recording of student demographics and performance on quizzes and a final exam across three sections of the course.
You will analyze the following variables in the grades.jasp Download grades.jaspdata set:
Variables and Definitions
Variable Definition
Review Attended review sessions? 1 = no; 2 = yes.
Final Final exam: number of correct answers.
Step 1: Write Section 1 of the DAA: Data Analysis Plan
Name the variables used in this analysis and whether they are categorical or continuous.
State a research question, null hypothesis, and alternate hypothesis for the independent samples t-test.
Step 2: Write Section 2 of the DAA: Testing Assumptions
Test for one of the assumptions of t tests – equality (homogeneity) of variances.
Create statistical output showing the Levene’s Test for Equality Variances.
Paste the table in the DAA template.
Interpret the Levene’s test.
Step 3: Write Section 3 of the DAA: Results & Interpretation
If the homogeneity assumption is not violated (Section 2), run the “Student” version of the independent samples t-test in the statistical software.
If the homogeneity assumption is violated, run the “Welch” version of the independent samples t-test in the statistical software.
Also run the “Descriptives” option to obtain the means and standard deviations for each group.
Paste the statistical software output of the t test into the DAA template. Below the output:
Report the means and standard deviations for each group.
State the results of the t test.
Interpret the statistical results against the null hypothesis and state whether it is rejected or not rejected.
Step 4: Write Section 4 of the DAA: Statistical Conclusions
Provide a brief summary of your analysis and the conclusions drawn about this t test.
Analyze the limitations of the statistical test and/or possible alternative explanations for your results.
Step 5: Write Section 5 of the DAA: Application
Analyze how you might use the independent samples t test in your field of study.
Name an independent variable and dependent variable that would work for such an analysis and why studying it may be important to the field or practice.
Submit your DAA Template as an attached Word document in the assessment area.
The following statistical analysis software is required to complete your assessments in this course:
Jeffreys’s Amazing Statistics Program (JASP).
Refer to the Tools and Software: JASP page on Campus for general information. Make sure that your statistical software is downloaded, installed, and running properly on your computer.
