12.1 Learning Outcomes
After completing this lab, you should be able to
- Conduct one-way and factorial ANOVAs in R Commander and SPSS
- Interpret the output of one-way and factorial ANOVAs from R Commander and SPSS
- Report the results of one-way and factorial ANOVAs in APA style
Before you begin, make sure you understand the following concepts from the lecture portion of the course
- The goal of ANOVA, including what types of research questions it can be used to test
- The difference between one-way and factorial ANOVA
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 7:30) 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).
You can download the dataset we will be using in this lab here. The dataset contains simulated (i.e., not real) data from 240 patients seeking treatment from an addictions treatment centre. Each patient is seeking treatment for the use of one of three substances: cannabis, alcohol, or opioids. Patients are randomly assigned to receive in-patient treatment (treatment condition) or to remain on a waitlist for treatment (control condition). The dataset contains the following variables:
rid: Research IDsubstance: Substance for which the participant is seeking treatment, with levelscannabis,alcohol, andopioidscondition: Experimental condition, with levelstreatmentandcontrolbam: Score on the Brief Addiction Monitor. Scores range from 0–66, with higher scores indicating greater levels of addictiongender: Gender, with levelswomanandman