\name{compareEMtoLM}
\alias{compareEMtoLM}
\title{Compares Evidence Models to Link Models. }
\description{
  Similar to the function \code{compareAMD}, only one of the arguments
  contains Evidence Models and the other contains Link Models.  In this
  case it matches each link model to the Evidence Model it came from and
  compares the two.
}
\usage{
compareEMtoLM(AMD, ADF, level = 0.05, chatty = TRUE)
}
\arguments{
  \item{AMD}{A parsed assessment model descripton containing evidence
    models.} 
  \item{ADF}{A parsed assessment description file containing link models.}
  \item{level}{Level of statistical test.}
  \item{chatty}{If \code{chatty} is true then intermediate results are
    printed to standard output.}
}
\details{
  Performs a parameter comparison similar to \code{compareAMD}, however,
  this time the ADF (containing link models) is compared to the AMD
  (containing evidence models).  Here each link model is compared to the
  evidence model from which it came.  If the evidence models referenced
  in the ADF cannot be found the in AMD, or the models have the same
  names but different variables, an error results.  Each test is
  performed with \code{compareDS} or \code{compareHD} for
  DiBello--Samejima or hyper-Dirichelet distributions respectively.

  The results of each test is a chi-square value which is accumulated
  across all tests.  If \code{chatty} is true, then the invidual test
  results are printed.
}
\value{
  \item{chi2}{Total Chi-squared value.}
  \item{df}{Total degrees of freedom.}
}
\references{
  http://research.ets.org/~ralmond/StatShop/dataFormats.html
}
\author{Russell Almond}
\note{ ~~further notes~~ }
\seealso{\code{\link{compareDS}}, \code{\link{compareHD}},
  \code{\link{parseAMD}}, \code{\link{compareAMD}}}
\examples{
#Assumes StatShop is installed on the test machine.
StatShop <- Sys.getenv("STATSHOP")
if (StatShop == "") {
  warn("StatShop not installed, skipping test.")
} else {
ltdir <- paste(StatShop,"TestScripts","LanguageExport",
          sep=.Platform$file.sep)

origAMD <- parseAMD(paste(ltdir,"Parametric-adf",
          "Assembly__Model__Parametric.amd.xml", sep=.Platform$file.sep))

derivedADF <- parseAMD(paste(ltdir,"Parametric-Random",
          "SixteenTasksR.amd.xml", sep=.Platform$file.sep))

result <- compareEMtoLM(origAMD,derivedADF)
print(result)
print(pchisq(result$chi2,result$df))

}
}
\keyword{htest}