scoreProbability.theta.gpc: Calculate the probability of each possible score for the...

In yuehmeir2/CATSimulator: Library for Simulation of Adaptive Item Selection

Description

Calculate the probability of each possible score for the given GPC items and a specific theta

Usage

scoreProbability.theta.gpc(item_pars, NC, theta)

Arguments

item_pars	a matrix of doubles, items by params. Must have columns for $PAR_* matching the $MODEL
NC	a vector of integers, one per row/item in item_pars, indicating the number of scoring categories for the item.
theta	a double. An ability level

Value

a matrix of doubles, items by scores, containing the probability of each possible score for the given items and a specific theta

Examples

  simulation = readRDS(system.file("example/passage-optimal.rds", package = "CATSimulator"))
  item_pars = as.matrix(simulation$itempool[,startsWith(colnames(simulation$itempool), "PAR_")])
  dimnames(item_pars) = list(simulation$itempool$ITEM_ID, colnames(simulation$itempool)[startsWith(colnames(simulation$itempool), "PAR_")])
  NC = itempool$NC[itempool$MODEL == "GPC"]
  theta = 2.0
  scoreProb = scoreProbability.theta.gpc(item_pars, NC, theta)
  options(digits=8, scipen=8)
  > scoreProb       0           1           2           3           4           5           6
  item001 0.054534047 0.279500656 0.665965296          NA          NA          NA          NA
  item002 0.077870790 0.307631523 0.614497687          NA          NA          NA          NA
  item003 0.208115753 0.278064930 0.513819317          NA          NA          NA          NA
  item004 0.194203063 0.176087171 0.197053893 0.242477093 0.190178780          NA          NA
  item005 0.250122827 0.155418381 0.181922731 0.242986174 0.169549887          NA          NA
  item006 ...114 total items/rows

yuehmeir2/CATSimulator documentation built on June 13, 2021, 7:02 p.m.