discrimSim: Simulates replicated difference tests

In perbrock/sensR: Thurstonian Models for Sensory Discrimination

Simulates replicated difference tests

Description

Simulates the outcome of sample.size replicated sensory difference tests (for any one of eight protocols: 2-AFC, 3-AFC, duotrio, tetrad, triangle, two-out-of-five, two-out-of-five with forgiveness and hexad tests) for a given d-prime value and a given overdispersion (default 0).

Usage

discrimSim(sample.size, replicates, d.prime, sd.indiv = 0,
           method = c("duotrio", "halfprobit", "probit", "tetrad",
             "triangle", "twoAFC", "threeAFC", "hexad", "twofive", "twofiveF"),
           double = FALSE)

Arguments

sample.size	the sample size - number of subjects
replicates	number of replications per subject
d.prime	the value of d-prime
method	the discrimination protocol
sd.indiv	the individual variability in d-prime values. A value of 0 (default) corresponds to complete independence
double	should the 'double' variant of the discrimination protocol be used? Logical scalar. Currently not implemented for "twofive", "twofiveF", and "hexad".

Details

The d-prime for each subject is a random draw from a normal distribution with mean d.prime and standard deviation sd.indiv. All negative values are set to zero.

Value

A vector of length sample.size with the number of correct answers for each subject.

Author(s)

Rune Haubo B Christensen and Per Bruun Brockhoff

References

Brockhoff, P.B. and Christensen, R.H.B. (2010). Thurstonian models for sensory discrimination tests as generalized linear models. Food Quality and Preference, 21, pp. 330-338.

See Also

triangle, twoAFC, threeAFC, duotrio, tetrad, twofive, twofiveF, hexad, discrimPwr, discrim, AnotA, discrimSS, samediff, findcr

Examples

## Running simulations:
discrimSim(sample.size = 10, replicates = 3, d.prime = 2,
           method = "triangle", sd.indiv = 1)

perbrock/sensR documentation built on Nov. 5, 2023, 10:41 a.m.