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, conserve = FALSE, conditioning = FALSE, .progressBar = TRUE)
A list of structural equations created using
An optional list of independence claims.
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.
data.frame of independence claims and their
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 reversable (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
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
Shipley, Bill. "A new inferential test for path models based on directed acyclic graphs." Structural Equation Modeling 7.2 (2000): 206-218.