Describe the model you will run

irt() is used to describe a model, it must be used in conjunction with set_engine(), and fit_wizirt().

irt(
  mode = "regression",
  item_type = NULL,
  rownames = NULL,
  tol = 1e-05,
  abs_fit = T
)

Arguments

mode

Must be "regression" currently.
item_type

Character. Must be one of "Rasch", "1PL", "2PL" or "3PL".
rownames

Optional unique row IDs for the data (i.e. examinee IDs). If omitted, uses 1:nrow(data).
tol

Numeric. Convergence criterion. Currently only implemented when engine is mirt.
abs_fit

Logical. Should absolute fit statistics be calculated? Increases time for estimation. Currently supported engine is "mirt".

Value

An object to be passed to fit_wizirt()

Examples

data("responses")
my_model <- irt(item_type = "Rasch") %>%
  set_engine(engine = "mirt") %>%
  fit_wizirt(data = responses[, -1])