Extracts the asymptotic variance-covariance matrix of the MLEs from either gpcm
, grm
,
ltm
, rasch
or tpm
objects.
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object |
an object inheriting from either class |
robust |
logical; if |
... |
additional arguments; currently none is used. |
a numeric matrix representing the estimated covariance matrix of the maximum likelihood estimates. Note that this
covariance matrix is for the parameter estimates under the additive parameterization and not under the usual IRT
parameterization; for more info check the Details section of grm
, ltm
,
rasch
, and tpm
.
Dimitris Rizopoulos d.rizopoulos@erasmusmc.nl
gpcm
,
grm
,
ltm
,
rasch
,
tpm
1 2 3 |
Questions? Problems? Suggestions? Tweet to @rdrrHQ or email at ian@mutexlabs.com.
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