Wald.test {Qval} | R Documentation |
Wald.test for two q-vecotrs
Description
This function flexibly provides the Wald test for any two q-vectors of a given item in the Q-matrix,
but requires that the two q-vectors differ by only one attribute. Additionally, this function needs
to accept a CDM.obj
.
Usage
Wald.test(CDM.obj, Q.i, Q.i.k, i = 1)
Arguments
CDM.obj |
An object of class |
Q.i |
A q-vector |
Q.i.k |
Another q-vector |
i |
the item you focusing on |
Details
Wald = \left[\mathbf{R} \times P_{i}(\mathbf{\alpha})\right]^{'}
(\mathbf{R} \times \mathbf{V}_{i} \times \mathbf{R})^{-1}
\left[\mathbf{R} \times P_{i}(\mathbf{\alpha})\right]
Value
An object of class list
containing the following components:
Wald.statistic |
The statistic of the Wald test. |
p.value |
The p value |
Examples
set.seed(123)
K <- 3
I <- 20
N <- 500
IQ <- list(
P0 = runif(I, 0.0, 0.2),
P1 = runif(I, 0.8, 1.0)
)
Q <- sim.Q(K, I)
data <- sim.data(Q = Q, N = N, IQ = IQ, model = "GDINA", distribute = "horder")
CDM.obj <- CDM(data$dat, Q)
Q.i <- c(1, 0, 0)
Q.i.k <- c(1, 1, 0)
## Discuss whether there is a significant difference when
## the q-vector of the 2nd item in the Q-matrix is Q.i or Q.i.k.
Wald.test.obj <- Wald.test(CDM.obj, Q.i, Q.i.k, i=2)
print(Wald.test.obj)
[Package Qval version 1.1.0 Index]