unsure-rater.R

library(rater)

# We have 'Unsure' ratings for the first three patients.
# We encode 'Unsure' = category 5.
anesthesia_w_unsure <- anesthesia
anesthesia_w_unsure[anesthesia$item %in% 1:3, "rating"] <- 5

# Taken from the rater() function's code.
J <- 5
K <- 4 + 1

N <- 8
p <- 0.6
on_diag <- N * p
off_diag <- N * (1 - p) / (K - 1)

beta_slice <- matrix(off_diag, nrow = K, ncol = K)
diag(beta_slice) <- on_diag

beta <- array(dim = c(J,K,K))
for (j in 1:5) {
  beta[j, , ] <- beta_slice
}
for (j in 1:5) {
  for (k in 1:5) {
    # Value will need tweaking!
    beta[j, k, ] <- rep(2, 5) 
  }
}

fit_w_unsure <- rater(anesthesia_w_unsure,
                      dawid_skene(beta = beta))
fit <- rater(anesthesia, "dawid_skene")

plot(fit, "theta")
plot(fit_w_unsure, "theta")