8.1 Learning Outcomes
After completing this lab, you should be able to
- Conduct paired samples t tests in R Commander and SPSS
- Interpret the output of a paired samples t test from R Commander and SPSS
- Report the results of a paired samples t test in APA style
Before you begin, make sure you understand the following concepts from the lecture portion of the course
- The goal of a paired samples t test, including what types of research questions it can be used to test
- The concepts behind paired samples t tests
- t distributions
- Degrees of freedom
- Critical t values
This lab will also draw on the following skills learned in earlier labs. You can review previous labs at any time.
- Loading data into R Commander and SPSS. You can review this skill in the videos on R Commander basics (beginning at 3:32) and SPSS basics (beginning at 0:48).
- Producing descriptive statistics in R Commander or SPSS. You can review this skill in the videos on Descriptive statistics in R Commander (beginning at 0:27) and Descriptive statistics in SPSS (beginning at 1:03).
- Creating new variables. You can review this skill in the videos on Variable transformations in R Commander (beginning at 1:30) or Variable transformations in SPSS (beginning at 0:32).
You can download the dataset we will be using in this lab here. In R Commander, you can load the Davis dataset directly from the carData package. For further information about the dataset and variables, refer to the documentation.