search for: bifactor

The function factor.scores is used with package ltm and others to estimate IRT type scores for various models. It inherits objects of class grm, gpcm and a few others. What I would like to do is to use the factor.scores function, but feed it my own item parameters (from a bifactor model where the 2PL parameters are adjusted for the bifactor structure). Does anybody have an idea of how this might be done? I can, of course, create a list, matrix or other object containing the item parameters, but factor.scores only inherits particular object classes. Any thoughts would be gr...

In an Sweave slide, I want to use sem::read.moments() and sem::specify.model(), which work by using scan() to read the following lines, up to the first blank line. However, Sweave throws an error: > Sweave("sem-thurstone.Rnw") Writing to file sem-thurstone.tex Processing code chunks ... 1 : term hide (label=arrests-setup) 2 : echo term hide (label=thurstone-data) Error: