salad {prefmod}

Data (ranks): Salad Dressings (Critchlow and Fligner)

Description

The dataset contains the rankings of four salad dressings concerning tartness by 32 judges, with values ranging from 1 (most tart) to 4 (least tart).

Usage

salad

Format

A data frame with 32 observations on 4 variables (A, B, C, D) each representing a different salad dressing.

References

Critchlow, D. E. & Fligner, M. A. (1991). Paired comparison, triple comparison, and ranking experiments as generalized linear models, and their implementation on GLIM. Psychometrika 56(3), 517–533.

Examples

# Example for object covariates
# fit object covariates:
# salads A - D have varying concentrations of acetic and gluconic acid.
# The four pairs of concentrations are
# A = (.5, 0), B = (.5, 10.0), C = (1.0, 0), and D = (0, 10.0),

conc <- matrix(c(.5, 0,  .5, 10,  1, 0,  0, 10), ncol = 2, byrow = TRUE)
sal  <- patt.design(salad, nitems = 4, resptype = "ranking")
X    <- as.matrix(sal[, 2:5]) 

glm(y ~ X, data = sal, family = poisson)