TestDesign: loadItemPool – R documentation

Become an expert in R — Interactive courses, Cheat Sheets, certificates and more!

loadItemPool

Load item pool

Description

loadItemPool is a data loading function to create an item_pool object. loadItemPool can read item parameters and standard errors from a data.frame or a .csv file.

Usage

loadItemPool(ipar, ipar_se = NULL, file = NULL, se_file = NULL, unique = FALSE)

Arguments

`ipar`	item parameters. Can be a `data.frame` or the file path of a .csv file. The content should at least include columns 'ID' and 'MODEL'.
`ipar_se`	(optional) standard errors. Can be a `data.frame` or the file path of a .csv file.
`file`	(deprecated) use `ipar` argument instead.
`se_file`	(deprecated) use `ipar_se` argument instead.
`unique`	if `TRUE`, item IDs must be unique to create a valid `item_pool` object. (default = `FALSE`)

Value

loadItemPool returns an item_pool object.

ni the number of items in the pool.
max_cat the maximum number of response categories across all items in the pool.
index the numeric item index of each item.
id the item ID string of each item.
model the object class names of each item representing an item model type. Can be item_1PL, item_2PL, item_3PL, item_PC, item_GPC, or item_GR.
NCAT the number of response categories of each item.
parms a list containing the item object of each item.
ipar a matrix containing all item parameters.
se a matrix containing all item parameter standard errors. The values will be 0 if the argument ipar_se was not supplied.
raw the original input data.frame used to create this object.

Examples

## Read from data.frame:
itempool_science <- loadItemPool(itempool_science_data)

## Read from file: write to tempdir() for illustration and clean afterwards
f <- file.path(tempdir(), "itempool_science.csv")
write.csv(itempool_science_data, f, row.names = FALSE)
itempool_science <- loadItemPool(f)
file.remove(f)

## TestDesign 1.1.0 - Deprecated arguments
## Not run: 
loadItemPool(ipar = "ipar.csv", ipar_se = "se.csv") # is equivalent to
loadItemPool(file = "ipar.csv", se_file = "se.csv") # pre 1.1.0

## End(Not run)

TestDesign

Optimal Test Design Approach to Fixed and Adaptive Test Construction

v1.2.2

GPL (>= 2)

Authors

Seung W. Choi [aut, cre] (<https://orcid.org/0000-0003-4777-5420>), Sangdon Lim [aut] (<https://orcid.org/0000-0002-2988-014X>)

Initial release

2021-01-26