rRUM_indept

In hmcdm: Hidden Markov Cognitive Diagnosis Models for Learning

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

library(hmcdm)

Load the spatial rotation data

N = dim(Design_array)[1]
J = nrow(Q_matrix)
K = ncol(Q_matrix)
L = dim(Design_array)[3]

(1) Simulate responses and response times based on the rRUM model

tau <- numeric(K)
for(k in 1:K){
  tau[k] <- runif(1,.2,.6)
}
R = matrix(0,K,K)
# Initial alphas
p_mastery <- c(.5,.5,.4,.4)
Alphas_0 <- matrix(0,N,K)
for(i in 1:N){
  for(k in 1:K){
    prereqs <- which(R[k,]==1)
    if(length(prereqs)==0){
      Alphas_0[i,k] <- rbinom(1,1,p_mastery[k])
    }
    if(length(prereqs)>0){
      Alphas_0[i,k] <- prod(Alphas_0[i,prereqs])*rbinom(1,1,p_mastery)
    }
  }
}
Alphas <- sim_alphas(model="indept",taus=tau,N=N,L=L,R=R,alpha0=Alphas_0)
table(rowSums(Alphas[,,5]) - rowSums(Alphas[,,1])) # used to see how much transition has taken place
Smats <- matrix(runif(J*K,.1,.3),c(J,K))
Gmats <- matrix(runif(J*K,.1,.3),c(J,K))
# Simulate rRUM parameters
r_stars <- Gmats / (1-Smats)
pi_stars <- apply((1-Smats)^Q_matrix, 1, prod)

Y_sim <- sim_hmcdm(model="rRUM",Alphas,Q_matrix,Design_array,
                   r_stars=r_stars,pi_stars=pi_stars)

(2) Run the MCMC to sample parameters from the posterior distribution

output_rRUM_indept = hmcdm(Y_sim,Q_matrix,"rRUM_indept",Design_array,
                           100,30,R = R)
output_rRUM_indept
summary(output_rRUM_indept)
a <- summary(output_rRUM_indept)
head(a$r_stars_EAP)

(3) Check for parameter estimation accuracy

(cor_pistars <- cor(as.vector(pi_stars),as.vector(a$pi_stars_EAP)))
(cor_rstars <- cor(as.vector(r_stars*Q_matrix),as.vector(a$r_stars_EAP*Q_matrix)))

AAR_vec <- numeric(L)
for(t in 1:L){
  AAR_vec[t] <- mean(Alphas[,,t]==a$Alphas_est[,,t])
}
AAR_vec

PAR_vec <- numeric(L)
for(t in 1:L){
  PAR_vec[t] <- mean(rowSums((Alphas[,,t]-a$Alphas_est[,,t])^2)==0)
}
PAR_vec

(4) Evaluate the fit of the model to the observed response

a$DIC
head(a$PPP_total_scores)
head(a$PPP_item_means)
head(a$PPP_item_ORs)

hmcdm documentation built on March 31, 2023, 8:07 p.m.