R: Generate an empirical objective function for item selection.

empiricalobjective {stuart}

R Documentation

Generate an empirical objective function for item selection.

Description

Generate an empirical objective function from default or empirical values for use in an item selection using STUART.

Usage

empiricalobjective(
  criteria = c("rmsea", "srmr", "crel"),
  add = c("chisq", "df", "pvalue"),
  x = NULL,
  n = 50,
  side = NULL,
  skew = FALSE,
  scale = 1,
  matrices = NULL,
  fixed = NULL,
  comparisons = NULL,
  ...
)

Arguments

`criteria`	A vector of names of criteria included in the objective function. Defaults to `c('rmsea', 'srmr', 'crel')`.
`add`	A vector of names of criteria not used in the objective function, but added in order to be included in the log of solutions.
`x`	Either a vector of values or an object of class `stuartOutput` from which to determine values in the objective function. If `NULL` (the default) values are generated from criteria-specific presets.
`n`	Number of values to use in function determining. Defaults to 50, meaning if `side = 'top'` the 50 largest values are used to determine discrimination and difficulty parameters for each criterion.
`side`	Which side good values are located at. `'top'` means large values are good (e.g. Reliability), `'bottom'` means small values are good (e.g. RMSEA), and `'middle'` means average values are good (e.g. factor correlations).
`skew`	Whether to account for skew in the distribution using the `psn()` function from the `sn`-Package. Defaults to `FALSE`, meaning a normal distribution is used.
`scale`	A numeric scale to use in weighting the objective component. Defaults to 1.
`matrices`	An object of class `stuartObjectiveMatrices` to include matrices (e.g. latent correlations) into the objective function.
`fixed`	An object of class `stuartFixedObjective` to include already previously defined fixed objectives.
`comparisons`	A vector of names of criteria included in the objective function which are related to model comparisons (e.g. when determining measurement invariance).
`...`	Additional arguments.

Value

Returns an object of class stuartFixedObjective

Author(s)