Harwell_Serlin: Harwell and Serlin Method for Nonparametric ANCOVA

In npANCOVA: Nonparametric ANCOVA Methods

Harwell and Serlin Method for Nonparametric ANCOVA

Description

Performs the Harwell and Serlin method using ranked response and covariate variables.

Usage

Harwell_Serlin(data, formula)

Arguments

data	A data frame containing the variables specified in the formula.
formula	An object of class "formula": a symbolic description of the model to be fitted. The structure should be 'response ~ covariate1 + ... + group'.

Value

A list containing the following components:

regression_equation

The summary of the fitted linear model.

anova

The ANOVA table from the fitted model.

statistics

The Harwell-Serlin test statistic.

df

The degrees of freedom for the test.

p_value

The p-value of the test.

data

The original data frame with added columns for ranks.

References

Harwell MR, Serlin RCJPB. An empirical study of a proposed test of nonparametric analysis of covariance. 1988;104(2):268.

Examples

# 1. Create a sample data frame
data <- data.frame(
  group = c(1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3),
  response = c(16, 60, 82, 126, 137, 44, 67, 87, 100, 142, 17, 28, 105, 149, 160),
  covariate1 = c(26, 10, 42, 49, 55, 21, 28, 5, 12, 58, 1, 19, 41, 48, 35),
  covariate2 = c(12, 21, 24, 29, 34, 17, 2, 40, 38, 36, 8, 1, 9, 28, 16)
)

# 2. Run the Harwell and Serlin method
results <- Harwell_Serlin(
  formula = response ~ covariate1 + covariate2 + group,
  data = data
)

# 3. View the results
print(results$p_value)
print(paste("Statistic:", results$statistics,"df:", results$df, "P-value:", results$p_value))

npANCOVA documentation built on Nov. 9, 2025, 5:06 p.m.