triangle.test: Make a Triangle test for a set of products

Description

Make a Triangle test for a set of products.

Usage

triangle.test (design, answer, preference = NULL)

Arguments

design

a data.frame corresponding to the design use to make the Triangle test (typically the ouput of the function triangle.design

answer

a vector of the answers of all the panelists; all the answer should be "X", "Y" or "Z"

preference

a vector of the preference of the panelists; all the answer should be "X", "Y" or "Z" (by default, there preference are not taken into account)

Value

Returns a list of matrices. Each matrix give the reult for all the pair of products:

nb.comp

a matrix with the number of comparisons done for each pair of products;

nb.ident

a matrix with the number of panelists who indicate the odd product for each pair of products;

p.value

a matrix with the p-value of the Triangle tests for each pair of products;

nb.recognition

estimation of the panelists who really perceived the difference between two product, for each pair of product;

maxML

Maximum Likelihood of the estimation of the number of panelists who really perceive the difference between the products;

confusion

estimation of the percentage of panelists who do not perceived the difference between two product, for each pair of product;

minimum

minimum of panelists who should detect the odd product to can say that panelists perceive the difference between the products, for each pair of products;

preference

number of times that product of row i is prefered that product in column j for the panelists who find the odd product.

Details

Triangle test: panelists receive three coded samples. They are told that two of the sample are the same and one is different. Panelists are asked to identify the odd sample.

Examples

Run this code

# NOT RUN {
design = triangle.design(nbprod = 4, nbpanelist = 6, bypanelist = 3)
answer = c("X","Y","Y","X","Z","X","Y","X","Z",
    "X","X","Z","X","Y","X","Z","X","Y")
triangle.test (design, answer)  
# }