R: Uniqueness prior to assist in item factor analysis
uniquenessPrior
R Documentation
Uniqueness prior to assist in item factor analysis
Description
To prevent Heywood cases, Bock, Gibbons, & Muraki (1988)
suggested a beta prior on the uniqueness (Equations 43-46).
The analytic gradient and Hessian are
included for quick optimization using Newton-Raphson.
Usage
uniquenessPrior(model, numFactors, strength = 0.1, name = "uniquenessPrior")
Arguments
model
an mxModel
numFactors
the number of factors.
All items are assumed to have the same number of factors.
strength
the strength of the prior
name
the name of the mxModel that is returned
Details
To reproduce these derivatives in maxima for the case
of 2 slopes (c and d), use the following code: