wald: Run Wald tests of separability and independence

In fsotoc/grtools: General Recognition Theory tools for the analysis of perceptual independence

Description

Run Wald tests of perceptual separability, decisional separability, and perceptual independence (see appendix of Soto et al., 2015), using the maximum likelihood parameter estimates stored in a grt_wind_fit object.

Usage

wald(fitted_model, cmats, estimate_hess=T)

Arguments

fitted_model	An object returned by grt_wind_fit
cmats	List of confusion matrices. Each entry in the list should contain the 4x4 confusion matrix from one individual. For a detailed description of how to create this list, see grt_wind_fit
estimate_hess	Indicates whether a numerical estimate of the Hessian should be obtained. If an estimate has been previously obtained and is stored in fitted_model, setting estimate_hess=F will save computing time.

Value

An object of class "grt_wind_fit," including information about Wald tests.

The function summary is used to obtain a summary of the model fit to data and the results of Wald tests.

References

Soto, F. A., Musgrave, R., Vucovich, L., & Ashby, F. G. (2015). General recognition theory with individual differences: A new method for examining perceptual and decisional interactions with an application to face perception. Psychonomic Bulletin & Review, 22(1), 88-111.

Examples

# Create list with confusion matrices # In this example, we enter data from
# an experiment with 5 participants. For each participant, inside the c(...),
# enter the data from row 1 in the matrix, then from row 2, etc.
cmats <- list(matrix(c(161,41,66,32,24,147,64,65,37,41,179,43,14,62,22,202),nrow=4,ncol=4,byrow=TRUE))
cmats[[2]] <- matrix(c(126,82,67,25,8,188,54,50,34,75,172,19,7,103,14,176),nrow=4,ncol=4,byrow=TRUE)
cmats[[3]] <- matrix(c(117,64,89,30,11,186,69,34,21,81,176,22,10,98,30,162),nrow=4,ncol=4,byrow=TRUE)
cmats[[4]] <- matrix(c(168,57,47,28,15,203,33,49,58,54,156,32,9,96,9,186),nrow=4,ncol=4,byrow=TRUE)
cmats[[5]] <- matrix(c(169,53,53,25,34,168,69,29,38,48,180,34,19,44,60,177),nrow=4,ncol=4,byrow=TRUE)

# fit the model to data
fitted_model <- grt_wind_fit(cmats)

#' # run the wald tests
fitted_model <- wald(fitted_model, cmats)

# see the results
summary(fitted_model)

fsotoc/grtools documentation built on Nov. 15, 2020, 5:14 a.m.