fit_wizirt: Run the irt model you described

In Pflegermeister/wizirt: A United API for IRT

Description

fit_wizirt() runs a model that has been built with irt() and set_engine().

Usage

fit_wizirt(object, data, control = parsnip:::control_parsnip(), ...)

Arguments

object	An object from set_engine()
data	An Person x Items matrix or dataframe of dichotomous response values (e.g. correct/incorrect). Rows are persons and columns are items, one row per person, one column per item. No other information allowed.

Value

Returns a list of class wizirt. spec is a list of information for the parsnip backend. printing spec prints a summary of the model run. elapsed contains the time it took the model to run. fit contains the model information:

• data is the data passed to the model

• model contains model fit information, including:

• engine a list with values pkg (the package used for estimation), ver (pkg version), func (functiong used from pkg), and call (call made to pkg)

• n_factors the number of factors estimated

• item_type the item type passed to wizirt (Rasch, 1PL, 2PL, or 3PL).

• estimation a list with information related to convergence. convergence a T/F value of whether the model converged, method the estimation method, criteria the convergence criteria, iterations the number of iterations it took for the model to converge, log_lik the loglikelihood at convergence, abs_fit the absolute fit of the model, df the number of parameters estimated.

• parameters a list of estimated parameters. coefficients is a data frame of estimated item-statistics and persons is a data frame of estimated person statistics.

• original_object is the object returned from the engine.

Examples

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

Pflegermeister/wizirt documentation built on Nov. 22, 2020, 8:27 p.m.