Full rankings of four salad dressings collected by Vargo (1989) and published in Critchlow and Fligner (1991). The salad dressings are formulated with varying percentages of acetic and gluconic acid as follows: A = (0.5, 0), B = (0.5, 10.0), C = (1.0, 0), and D = (0, 10.0). The salad dressings are ranked by tartness from 1 (most tart) to 4 (least tart).
Format
A data frame with 32 records across 4 variables: A, B, C, and
D, representing the four salad dressings.
Source
Critchlow, D. E. and 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.
References
Vargo, M. D. (1989) Microbiological spoilage of a moderate acid food system using a dairy-based salad dressing model. Unpublished masters thesis, Ohio State University, Department of Food Science and Nutrition, Columbus, OH, USA.
Examples
# create data frame of acetic and gluconic acid concentrations
features <- data.frame(salad = LETTERS[1:4],
acetic = c(0.5, 0.5, 1, 0),
gluconic = c(0, 10, 0, 10))
# fit Plackett-Luce model based on covariates
res_PLADMM <- pladmm(salad, ~ acetic + gluconic, data = features, rho = 8)
# worth (relative tartness) as predicted by linear function of features
itempar(res_PLADMM)
#> Item response item parameters (PLADMM):
#> A B C D
#> 0.04061 0.62840 0.20874 0.12225