lsem.test: Test a Local Structural Equation Model Based on Bootstrap

In alexanderrobitzsch/sirt: Supplementary Item Response Theory Models

Test a Local Structural Equation Model Based on Bootstrap

Description

Performs global and parameter tests for a fitted local structural equation model. The LSEM must have been fitted and bootstrap estimates of the LSEM model must be available for statistical inference. The hypothesis of a constant parameter is tested by means of a Wald test. Moreover, regression functions can be specified and tested if these are specified in the argument models.

Usage

lsem.test(mod, bmod, models=NULL)

Arguments

mod	Fitted LSEM object
bmod	Fitted LSEM bootstrap object. The argument bmod can also be missing.
models	List of model formulas for named LSEM model parameters

Value

List with following entries

wald_test_global	Global Wald test for model parameters
test_models	Output for fitted regression models. The test for parameter heterogeneity is included in chisq_het, while the test of a sufficient fit of a parameter curve is included in chisq_fit.
parameters	Original model parameters after fitting (i.e., smoothing) a particular parameter using a regression model specified in models.
parameters_boot	Bootstrapped model parameters after fitting (i.e., smoothing) a particular parameter using a regression model specified in models.

See Also

See also lsem.estimate for estimating LSEM models and lsem.bootstrap for bootstrapping LSEM models.

Examples

## Not run: 
#############################################################################
# EXAMPLE 1: data.lsem01 | Age differentiation and tested models
#############################################################################

data(data.lsem01, package="sirt")
dat <- data.lsem01

# specify lavaan model
lavmodel <- "
        F=~ v1+v2+v3+v4+v5
        F ~~ 1*F
    "

# define grid of moderator variable age
moderator.grid <- seq(4,23,1)

#-- estimate LSEM with bandwidth 2
mod <- sirt::lsem.estimate( dat, moderator="age", moderator.grid=moderator.grid,
               lavmodel=lavmodel, h=2, std.lv=TRUE)
summary(mod)

#-- bootstrap model
bmod <- sirt::lsem.bootstrap(mod, R=200)

#-- test models
models <- list( "F=~v1"=y ~ m + I(m^2),
                "F=~v2"=y ~ I( splines::bs(m, df=4) ) )
tmod <- sirt::lsem.test(mod=mod, bmod=bmod, models=models)
str(tmod)
sirt::print_digits(wald_test_global, 3)
sirt::print_digits(test_models, 3)

## End(Not run)

alexanderrobitzsch/sirt documentation built on Dec. 1, 2024, 2:18 a.m.