ATLASResearch
methods
Quantitative/ Analysis

ANOVA

Compare group means and planned contrasts

Analysis of variance expresses mean comparisons as a linear model with categorical predictors. One-way ANOVA compares levels of one factor; factorial ANOVA includes several factors and their interactions. Repeated-measures ANOVA models related conditions within participants. An omnibus F-test and specific planned contrasts answer different questions and should be reported separately.

WHEN IT FITS

Use when continuous outcomes are compared across experimental factors or several groups. Specify meaningful contrasts, the experimental unit and any repeated observations before examining the outcomes.

Strengths

  • Unifies group comparisons within one model
  • Tests interactions and planned contrasts explicitly

Limitations

  • An omnibus result does not identify which groups differ
  • Imbalance, unequal variances and dependence require appropriate extensions

Know the boundary

A main effect averaged across an interaction may obscure the actual pattern; inspect conditional comparisons.

USED ACROSS
Banking & financeBusiness & MBAPsychologyComputer scienceEducation