Provides estimates and standard errors of d-prime and tau for the two
alternative (2-AC) discrimination protocol. The 2-AC protocol is
equivalent to a 2-AFC protocol with a "no-difference" option.
Usage
twoAC(data, ...)
Arguments
data
a numeric vector of length 3 with the number of observations in the
three response categories. If the third element is larger than the
first element, then the estimate of d-prime will be positive.
...
not currently used
Value
An object of class twoAC with elements
d.primethe estimate of d-prime
tauthe estimate of tau
coefficientsnamed vector of coefficients; d-prime and tau
vcovvariance-covariance matrix of the parameter estimates
datathe data supplied to the function
callthe matched call
logLikthe value of the log-likelihood at the maximum likelihood estimates
Details
confint,
profile and
print methods are implemented for twoAC objects.
References
Christensen, R.H.B. and Brockhoff, P.B. (2010). Estimation of the
Thurstonian model for the 2-AC protocol.
Manuscript for Food Quality and Preference.