lw2: bi-factor irt scoring

In pbotter42/irts: IRT scoring.

Description

This package computes the original Lord-Wingersky Algorithm for unidimensional IRT models, as well as the Lord-Wingersky Algorithm 2.0(Cai, 2015).

Usage

lw2(n_quad, theta_min, theta_max, item_params, ic_index)

Arguments

ic_index

Value

out

Examples

item_params <- list()   
item_params[[1]] <- list()   
item_params[[1]]["slope_gen"] <- 1.2   
item_params[[1]]["slope_spec"] <- 1   
item_params[[1]][["thr"]] <- list()   
item_params[[1]][["thr"]] <- c(-1)   
item_params[[2]] <- list()   
item_params[[2]]["slope_gen"] <- 1.2   
item_params[[2]]["slope_spec"] <- 1   
item_params[[2]][["thr"]] <- list()   
item_params[[2]][["thr"]] <- c(-.6)   
item_params[[3]] <- list()   
item_params[[3]]["slope_gen"] <- 1   
item_params[[3]]["slope_spec"] <- .8   
item_params[[3]][["thr"]] <- list()   
item_params[[3]][["thr"]] <- c(-.2)   
item_params[[4]] <- list()   
item_params[[4]]["slope_gen"] <- 1   
item_params[[4]]["slope_spec"] <- .8   
item_params[[4]][["thr"]] <- list()   
item_params[[4]][["thr"]] <- c(.2)   
item_params[[5]] <- list()   
item_params[[5]]["slope_gen"] <- .8   
item_params[[5]]["slope_spec"] <- 1.2   
item_params[[5]][["thr"]] <- list()   
item_params[[5]][["thr"]] <- c(.6)   
item_params[[6]] <- list()   
item_params[[6]]["slope_gen"] <- .8   
item_params[[6]]["slope_spec"] <- 1.2   
item_params[[6]][["thr"]] <- list()   
item_params[[6]][["thr"]] <- c(1)   

example1 <- lw2(n_quad = 5,   
                       theta_min = -2,
                       theta_max = 2,   
                       item_params = item_params,   
                       ic_index = c(1,1,2,2,3,3))

pbotter42/irts documentation built on May 7, 2019, 3:15 p.m.