7.1 Learning Objectives

After completing this lab, you should be able to

  • Conduct independent samples t tests in R Commander and SPSS
  • Interpret the output of an independent samples t test from R Commander and SPSS
  • Report the results of an independent 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 an independent samples t test, including what types of research questions it can be used to test
  • The concepts behind independent 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.

You can download the dataset we will be using in this lab here. In R Commander, you can load the Wells dataset directly from the carData package. For further information about the dataset and variables, refer to the documentation.