Effect Size for ANOVA

Compute eta-squared and partial eta-squared for all terms in an ANOVA model.

eta_squared(model)

partial_eta_squared(model)

Arguments

model

an object of class aov or anova.

Value

a numeric vector with the effect size statistics

Functions

• eta_squared(): compute eta squared

• partial_eta_squared(): compute partial eta squared.

Examples

# Data preparation
df <- ToothGrowth
df$dose <- as.factor(df$dose)

# Compute ANOVA
res.aov <- aov(len ~ supp*dose, data = df)
summary(res.aov)
#>             Df Sum Sq Mean Sq F value   Pr(>F)    
#> supp         1  205.4   205.4  15.572 0.000231 ***
#> dose         2 2426.4  1213.2  92.000  < 2e-16 ***
#> supp:dose    2  108.3    54.2   4.107 0.021860 *  
#> Residuals   54  712.1    13.2                     
#> ---
#> Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

# Effect size
eta_squared(res.aov)
#>       supp       dose  supp:dose 
#> 0.05948365 0.70286419 0.03137672 
partial_eta_squared(res.aov)
#>      supp      dose supp:dose 
#> 0.2238254 0.7731092 0.1320279