marginal_psychometrics: Marginal performance statistics for identification systems

In mcbeem/giftedCalcs: Psychometrics for Gifted Program Identification

Marginal performance statistics for identification systems

Description

This function calculates marginal performance statistics for one- and two-stage identification systems. A two-stage system is one in which an initial nomination process is used to select students who are tested on the confirmatory assessment.

Usage

marginal_psychometrics(
  relyt = 0.9,
  test.cutoff,
  valid = 1e-07,
  nom.cutoff = 1e-07,
  mu = 0
)

Arguments

relyt	Confirmatory test reliability coefficient. Range (0, 1). Must not be exactly 0 or 1. Defaults to .9.
test.cutoff	Confirmatory test cutoff percentile. Range (0, 1). Must not be exactly 0 or 1.
valid	Nomination validity coefficient. Controls the relatedness of the nomination scores and the confirmatory test scores. Range (0, 1). Must not be exactly 0 or 1, and must be less than the square root of the test reliability.
nom.cutoff	Nomination cutoff percentile. Range (0, 1). Must not be exactly 0 or 1.
mu	Population mean true score on a standardized (z-score) metric. Defaults to zero.

Details

Two-stage system results are reported if arguments valid and nom.cutoff are provided. Otherwise, one-stage results are reported.

The function returns a list containing the following:

sensitivity: The proportion of qualifying students who are identified.

IIR: Incorrect identification rate; the proportion of identified students who do not qualify.

nom.rate: Nomination rate; the proportion of students who are nominated, which controls testing costs. (Two-stage only).

nom.passrate: The proportion of nominated students who go on to be identified. (Two-stage only)

identification.rate: The proportion of the student population that is identified.

Examples

# one-stage system
marginal_psychometrics(mu = 0, test.cutoff = .9, relyt = .95)

# two-stage system
marginal_psychometrics(
  mu = 0, test.cutoff = .9,
  nom.cutoff = .8, relyt = .95, valid = .7
)

mcbeem/giftedCalcs documentation built on May 3, 2022, 3:34 a.m.