Modeling local dependence in longitudinal IRT models

TY - JOUR

T1 - Modeling local dependence in longitudinal IRT models

AU - Larsen, Maja Olsbjerg

AU - Christensen, Karl Bang

PY - 2015/1/1

Y1 - 2015/1/1

N2 - Measuring change in a latent variable over time is often done using the same instrument at several time points. This can lead to dependence between responses across time points for the same person yielding within person correlations that are stronger than what can be attributed to the latent variable. Ignoring this can lead to biased estimates of changes in the latent variable. In this paper we propose a method for modeling local dependence in the longitudinal 2PL model. It is based on the concept of item splitting, and makes it possible to correctly estimate change in the latent variable.

AB - Measuring change in a latent variable over time is often done using the same instrument at several time points. This can lead to dependence between responses across time points for the same person yielding within person correlations that are stronger than what can be attributed to the latent variable. Ignoring this can lead to biased estimates of changes in the latent variable. In this paper we propose a method for modeling local dependence in the longitudinal 2PL model. It is based on the concept of item splitting, and makes it possible to correctly estimate change in the latent variable.

U2 - 10.3758/s13428-014-0553-0

DO - 10.3758/s13428-014-0553-0

M3 - Journal article

C2 - 25552424

SN - 1554-351X

VL - 47

SP - 1413

EP - 1424

JO - Behavior Research Methods

JF - Behavior Research Methods

IS - 4

ER -