W8 ANOVA + W9 Post Hoc Tests

Residuals

The difference between an observed value and the value predicted by a statistical model.

F-statistic

A ratio of variance between groups to variance within groups, used in ANOVA to test group differences.

Factor

An independent variable in an experiment or ANOVA with two or more levels.

ANOVA

A statistical test used to determine if there are significant mean differences among three or more groups.

Eta Squared

An effect size measure showing the proportion of total variance explained by a factor.

Partial Eta Squared

An effect size measure showing the proportion of variance explained by a factor relative to its variance plus error.

Studentised Range Statistic (q)

A test statistic used in post hoc tests like Tukey’s HSD to compare ranges of means.

Post Hoc Analysis

Tests conducted after a significant ANOVA to identify which group means differ.

Tukey’s Honestly Significant Difference Test (HSD)

A post hoc test that compares all pairs of means while controlling family-wise error rate.

Family-Wise Error Rate

The probability of making at least one Type I error across multiple comparisons.

Per Comparison Error Rate

The probability of a Type I error in a single test, ignoring multiple comparisons.

A Priori Comparison

A comparison between groups planned before data collection or analysis, based on hypotheses.