, Volume 70, Issue 1, pp 213–216

A note on item information in any direction for the multidimensional three-parameter logistic model


DOI: 10.1007/s11336-003-1129-6

Cite this article as:
Bryant, D.U. Psychometrika (2005) 70: 213. doi:10.1007/s11336-003-1129-6


The purpose of this note is twofold: (a) to present the formula for the item information function (IIF) in any direction for the Multidimensional 3-Parameter Logistic (M3-PL) model and (b) to give the equation for the location of maximum item information (θmax) in the direction of the item discrimination vector. Several corollaries are given. Implications for future research are discussed.


item informationmeasurement directionmultidimensional measurementmaximum informationthree-parameter logistic model

Copyright information

© The Psychometric Society 2005

Authors and Affiliations

  1. 1.University Of Central FLorida At OrlandoUSA
  2. 2.Department of PsychologyUniversity of Central FloridaOrlandoUSA