discrimSim: Simulates replicated difference tests

Description Usage Arguments Details Value Author(s) References See Also Examples

View source: R/discrim.R

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

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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

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

sensR documentation built on May 2, 2019, 9:43 a.m.