infoFunc {conquestr}

R Documentation

infoFunc

Description

Calculate test information function, given a vector of item difficulties and a vector of abilities. Returns a data frame that can be easily plotted.

Usage

infoFunc(
  myItems,
  myAbilities,
  type = "empirical",
  minTheta = NA,
  maxTheta = NA,
  stepTheta = NA
)

Arguments

myItems	A vector of item deltas.
myAbilities	A vector of person abilities.
type	A character String. Should the test information be calculated empirically ("empirical" - default) or analytically using moments of distribution ("approx").
minTheta	The smallest value of ability PDF to plot.
maxTheta	The largest value of ability PDF to plot.
stepTheta	The increment to iterate over the ability PDF. Defaults to 0.01.

Value

A data frame.

Examples

myInfo<- infoFunc(runif(10, -2, 3), rnorm(1000, 0, 1))

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