model_mixed: Mixed-format model

In Rirt: Data Analysis and Parameter Estimation Using Item Response Theory

Description

Common computations and operations for the mixed format model

Usage

model_mixed_gendata(n_p, n_3pl = 0, n_gpcm = 0, n_grm = 0, n_c, ...)

model_mixed_prob(t, items, D = 1.702)

model_mixed_info(t, items, D = 1.702, combine = TRUE)

model_mixed_lh(u, t, items, D = 1.702, log = FALSE, combine = TRUE)

Arguments

n_p	the number of test takers
n_3pl	the number of 3pl items
n_gpcm	the number of gpcm items
n_grm	the number of grm items
n_c	the number of score categories for polytomous items
...	additional arguments
t	ability parameters, a vector
items	a list of '3pl', 'gpcm', and 'grm' items
D	the scaling constant, default=1.702
combine	TRUE to combine results from list to matrix
u	the response data, a 2d matrix
log	TRUE to return log-likelihood

Value

model_mixed_gendata returns a list of generated responses, ability paramters and items

model_mixed_prob returns a list of probabilities for '3pl', 'gpcm', and 'grm' items

model_mixed_info returns a list or matrix of information

Examples

# generate 10 3pl items, 5 gpcm items and 5 grm items
model_mixed_gendata(10, n_3pl=10, n_gpcm=5, n_grm=5, n_c=3)
# generate 5 gpcm items and 5 grm items, 4 score categories each
model_mixed_gendata(10, n_gpcm=5, n_grm=5, n_c=4)
# generate 5 people and 4 items of each type
with(model_mixed_gendata(n_p=5, n_3pl=4, n_gpcm=4, n_grm=4, n_c=3), 
     model_mixed_prob(t, items))
     
# generate 10 people and 5 gpcm and 5 grm items
with(model_mixed_gendata(n_p=10, n_gpcm=4, n_grm=4, n_c=3), 
     model_mixed_prob(t, items))
with(model_mixed_gendata(10, 4, 4, 4, 3), model_mixed_info(t, items)) 
with(model_mixed_gendata(10, 0, 4, 4, 3), model_mixed_info(t, items)) 
with(model_mixed_gendata(10, 4, 4, 4, 3), model_mixed_lh(u, t, items))

Rirt documentation built on Oct. 30, 2019, 12:13 p.m.