get_cat_response_data {irt}

Extracts the response data of CAT output.

Description

This function extracts the response data from a single cat_output object or a list of cat_output objects and returns a Response_set object that contains the administered items of each simulee or a matrix or responses.

If cd, cat design, object is given, then the item pool in the cd will be used.

Usage

get_cat_response_data(
  cat_sim_output,
  cd = NULL,
  output_type = c("Response_set", "matrix"),
  remove_na = FALSE,
  attach_summary = FALSE
)

Arguments

cat_sim_output

This is a list object containing elements that are cat_output class.

cd

A cat_design object that is created by function create_cat_design.

output_type

A string that specifies the output type. Available options are "Response_set" which returns a Response_set object and "matrix" which returns a matrix. If attach_summary = TRUE and output_type = "matrix", a data frame will be returned instead of a matrix. The default value is "Response_set".

remove_na

If TRUE, the columns that are all NA will be removed.

attach_summary

If TRUE and output_type = "matrix", the summary of each CAT will be attached to the beginning of the response string as columns. The default value is FALSE. When output_type = "Response_set", CAT summary will automatically added to each Response object of the output within misc field.

Value

Depending on the output_type, the function returns the response matrix of adaptive tests. If the input is a list of cat_output, then the rows will represent examinees and columns will represent items.

Author(s)

Emre Gonulates

See Also

cat_sim

Examples

n <- 40 # number of items
ip <- generate_ip(n = n)
cd <- create_cat_design(ip = ip, next_item_rule = 'mfi',
                        termination_rule = 'max_item',
                        termination_par = list(max_item = 10))
cat_data <- cat_sim(true_ability = rnorm(10), cd = cd)
resp_set <- get_cat_response_data(cat_sim_output = cat_data, cd)
resp_set

# Get the examinee_id of third simulee:
resp_set[[3]]$examinee_id
# Extract the true theta of the third examinee:
resp_set[[3]]$true_ability
# Extract the final estimated theta of the third examinee:
resp_set[[3]]$est_ability
# Extract the final standard error of the third examinee:
resp_set[[3]]$se


# Alternatively, output can be a matrix:

resp_matrix <- get_cat_response_data(cat_sim_output = cat_data,
                                     output_type = "matrix")
resp_matrix

# If cat design provided, the matrix columns will be sorted as the
# item pool used for the simulation:
resp_matrix <- get_cat_response_data(cat_sim_output = cat_data, cd = cd,
                                     output_type = "matrix")
resp_matrix

# Additionally, remove the colums which has all NA values:
resp_matrix <- get_cat_response_data(cat_sim_output = cat_data, cd = cd,
                                     remove_na = TRUE,
                                     output_type = "matrix")
resp_matrix