informationWrightMap {conquestr}R Documentation

informationWrightMap

Description

Plots test information function, relative to ability density, and item locations.

Usage

informationWrightMap(
  myItems,
  myAbilities,
  type = "empirical",
  minTheta = NA,
  maxTheta = NA,
  stepTheta = NA,
  scaleInfo = 1
)

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.

scaleInfo

A scaling factor to apply to the plot of tesr information. Because ability distribution is a PDF with area one, and a test information function has area L, this can make the plot more interpretable. Defaults to 1.

Value

A ggplot2 object.

Examples

myInfoPlot<- informationWrightMap(runif(10, -2, 3), rnorm(1000, 0, 1), minTheta=-10, maxTheta=10)

[Package conquestr version 0.9.96 Index]