Applies the adaptive test algorithm to determine the next step: administer the next item or stop test and return D-score.

Usage

dcat(
  txt = "",
  instrument = "gs1",
  key = NULL,
  population = NULL,
  p = 50,
  min_length = 0,
  sem_rule = 1.726,
  domain_set = "GFCLS",
  k_domain = 0,
  session = "",
  format = "3.1",
  ...
)

Arguments

txt: A JSON string, URL or file
instrument: character vector with instrument names to use to select items
key: String. They key identifies 1) the difficulty estimates pertaining to a particular Rasch model, and 2) the prior mean and standard deviation of the prior distribution for calculating the D-score. The default key NULL sets key = "gsed2510". View dscore::builtin_keys for an overview of the available keys.
population: String. Name of the reference population
p: percentage to pass the item, difficulty in percentile units
min_length: numeric value for minimum number of items to administer, default is set to min_length = 0.
sem_rule: numeric target for sem can be estimated based on Cohen's d from sem_rule().
domain_set: String. The name of the set of domains to use. See with(builtin_domaintable, table(set, domain)) for the domain names in each set.
k_domain: integer. Minimum target for the number of items in each domain, default is set to k_domain = 0.
session: Optional session key if data is already uploaded to sitehost.
format: String. JSON data schema version number. There are currently three schemas supported: "1.0", "1.1", "2.0", "3.0" and "3.1". Formats "1.0" and "1.1" are included for backward compatibility only. Use format = "3.1" for new applications.
...: Ignored

Value

A string with an item name or a table.

Author

Iris Eekhout 2025

Examples

txt <- system.file("examples", "example_v3.1.json", package = "bdsreader")
dcat(txt = txt, p = 50)
#> [1] "gs1lgc117"
txt <- "~/OneDrive - TNO/Documents/GitHub/james/data-raw/test_data.json"
dcat(txt = txt, p = 50)
#> [1] "gs1cgc128"