ScheffeTest {Analitica}R Documentation

Scheffé Test for Multiple Comparisons

Description

Performs Scheffé's post hoc test after fitting an ANOVA model. This test compares all possible pairs of group means, using a critical value based on the F-distribution.

Usage

ScheffeTest(modelo, alpha = 0.05)

Arguments

modelo

An object of class aov or lm representing an ANOVA model.

alpha

Significance level (default is 0.05).

Details

The Scheffé test is a conservative method, making it harder to detect significant differences, but reducing the likelihood of Type I errors (false positives). It is especially appropriate when the comparisons were not pre-planned and the number of contrasts is large.

Assumptions: normally distributed residuals and homogeneity of variances.

Advantages: - Very robust to violations of assumptions. - Suitable for complex comparisons, not just pairwise.

Disadvantages: - Very conservative; reduced power. - Not ideal for detecting small differences.

Value

An object of class "scheffe" and "comparaciones", containing:

References

Scheffé, H. (1953). "A method for judging all contrasts in the analysis of variance." Biometrika, 40(1/2), 87–104. <https://doi.org/10.1093/biomet/40.1-2.87>

Examples

data(d_e, package = "Analitica")
mod <- aov(Sueldo_actual ~ as.factor(labor), data = d_e)
resultado <- ScheffeTest(mod)
summary(resultado)
plot(resultado)

[Package Analitica version 1.8.5 Index]