The type of statistical test you use will depend on the number of predictor/independent variables in your study, how they are measured (nominal or continuous), and, if the independent variable is nominal, how many levels it has. It will also depend on how your outcome/dependent variable is measured (nominal or continuous); however, in this book, we only covered statistical tests for continuous dependent variables.

By Predictor/Independent Variable Type

One way to determine what type of statistical test you should use is to answer the questions below about your predictor/independent variable(s) and use the flow chart linked below.

• How are your predictor/independent variable(s) measured? (Nominal or continuous)
• How many predictor/independent variable(s) does your study have?
• For any nominal predictor/independent variables:
  • How many levels does the predictor/independent variable have?
  • Is the nominal predictor/independent variable within-subjects or between-subjects?

What Statistical Test Should I Use? Flowchart [PDF]

By Statistical Test

Below is a list of each type of statistical test covered in this book (and a few extras) and when to use that test.

Correlation

• Two continuous variables

Multiple Regression

• Multiple predictor variables, all continuous or both continuous and nominal
• A continuous outcome variable

Independent t-test

• One independent variable that is:
  • Nominal
  • Between-subjects
  • Has two levels
• A continuous outcome variable

Paired Samples t-test

• One independent variable that is:
  • Nominal
  • Within-subjects
  • Has two levels
• A continuous outcome variable

Between-Subjects (Independent) One-way ANOVA

• One independent variable that is:
  • Nominal
  • Between-subjects
  • Has three or more levels
• A continuous outcome variable

Use the ANOVA option in jamovi.

Repeated Measures One-way ANOVA

• One independent variable that is:
  • Nominal
  • Within-subjects
  • Has three or more levels
• A continuous outcome variable

Independent Factorial ANOVA (including Two-way ANOVA)

• Two or more independent variables that are:
  • Nominal
  • Between-subjects
• A continuous outcome variable

Use the ANOVA option in jamovi.

Repeated Measures Factorial ANOVA

• Two or more independent variables that are:
  • Nominal
  • Within-subjects
• A continuous outcome variable

Mixed Factorial ANOVA

• At least one independent variable that is:
  • Nominal
  • Between-subjects
• At least one independent variable that is:
  • Nominal
  • Within-subjects
• A continuous outcome variable