Evaluation of conditional independence claims to be used in determining the goodness-of-fit for piecewise structural equation models.
dSep(
modelList,
basis.set = NULL,
direction = NULL,
interactions = FALSE,
conserve = FALSE,
conditioning = FALSE,
.progressBar = TRUE
)Returns a data.frame of independence claims and their
significance values.
A list of structural equations created using psem.
An optional list of independence claims.
A vector of claims defining the specific
directionality of independence claims; for use in special cases (see
Details).
whether interactions should be included in independence claims. Default is FALSE
Whether the most conservative P-value should be returned; for use in special cases (see Details). Default is FALSE.
Whether the conditioning variables should be shown in the summary table. Default is FALSE.
An optional progress bar. Default is TRUE.
Jon Lefcheck <lefcheckj@si.edu>, Jarrett Byrnes
In cases involving non-normally distributed responses in the independence
claims that are modeled using generalized linear models, the significance of
the independence claim is not reversible (e.g., the P-value of Y ~ X is not
the same as X ~ Y). This is due to the transformation of the response via
the link function. In extreme cases, this can bias the goodness-of-fit
tests. summary.psem will issue a warning when this case is present
and provide guidance for solutions.
One solution is to specify the directionality of the relationship using the
direction argument, e.g. direction = c("X <- Y"). Another is
to run both tests (Y ~ X, X ~ Y) and return the most conservative (i.e.,
lowest) P-value, which can be toggled using the conserve = TRUE
argument.
Shipley, Bill. "A new inferential test for path models based on directed acyclic graphs." Structural Equation Modeling 7.2 (2000): 206-218.
basisSet