\name{amd}
\alias{amd}
\title{ Creates an Assessment Model Description object }
\description{
  An Assessment Model Description object is a collection of models which
  describe an assessment.  The model object contain \code{gmModel}
  objects which describe the indivdual models in the assessment.
  Usually this is built by reading an \code{amd.xml} file.
}
\usage{
amd(studentModels, evidenceModels, linkModels,
    statistics = list(), missingCodes = list(), filename = NULL)
}
\arguments{
  \item{studentModels}{A list \code{gmModel} objects describing the
    \code{studentModels} used in this assessment. } 
  \item{evidenceModels}{A list \code{gmModel} objects describing the
    \code{evidenceModels} used in this assessment. } 
  \item{linkModels}{A list \code{gmModel} objects describing the
    \code{linkModels} used in this assessment.}
  \item{statistics}{A list of \code{Statistic} objects used to describe
    reporting statistics available with this assessment.}
  \item{missingCodes}{A list of \code{MissingCode} object used to
    describe treatment of missing responses.}
  \item{filename}{Name of the \code{amd.xml} file this object was built
    from.} 
}
\details{
  An assessment description can contain the following types of objects:
  \describe{
  \item{Student Model}{A description of the state of knowledge of the
    student.  Usually all variables in the student model are latent (or
    demographic).}
  \item{Evidence Model}{A generic description of how to score tasks from
    a Task Model (a family of tasks).}
  \item{Link Model}{A task specific version of a link model.}
}
  This is basically a structured collection of model objects.
}
\value{
  An object of class \code{amd} with fields:
  \item{studentModels}{A list \code{gmModel} objects describing the
    \code{studentModels} used in this assessment. } 
  \item{evidenceModels}{A list \code{gmModel} objects describing the
    \code{evidenceModels} used in this assessment. } 
  \item{linkModels}{A list \code{gmModel} objects describing the
    \code{linkModels} used in this assessment.} 
  \item{statistics}{A list of \code{Statistic} objects used to describe
    reporting statistics available with this assessment.}
  \item{missingCodes}{A list of \code{MissingCode} object used to
    describe treatment of missing responses.}
  \item{filename}{Name of the \code{amd.xml} file this object was built
    from.} 

}
\references{
  \url{http://research.ets.org/~ralmond/StatShop/dataFormats.html}
}
\author{Russell Almond }
\seealso{\code{\link{parseAMD}}, \code{\link{printAMDParameterValues}},
  \code{\link{gmModel}}, \code{\link{compareAMD}},
  \code{\link{MissingCode}},
  \code{\link{Statistic}}.
}
\examples{
# Assumes StatShop is installed on the test machine.
StatShop <- Sys.getenv("STATSHOP")
if (StatShop == "") {
  warn("StatShop not installed, skipping test.")
} else {

## IMPORTANT:  CD to directory before reading.  If you don't R won't be
## able to find GM files.
setwd(paste(StatShop,"TestScripts","ICT","Version0","Hybrid","FixedContext",
      sep=.Platform$file.sep))

## This command finds the name of the AMD files in the current
## directory.  Rest of the script assumes that the first one is the
## one you want to use.
amds <- system("ls *.amd.xml",TRUE)

## This version of the command for Assessment Description files, it
## looks at link models.
anAmp <- parseAMD(amds[1])

### This command builds the V-Matrix
printAMDParameterValues(anAmp)
}
}
\keyword{interface}