Methods for Longitudinal Equating

Project Description

Understand if univariate equating solutions can recover a within-examinee growth curve. If not, propose a multivariate solution capable of recovering the within-examinee growth curve.

Research Design

1. Generate item responses

2. Univariate equating

   1. Mean equating
   2. Linear equating
   3. Equipercentile equating

3. Compare equated benchmark scores to longitudinal anchor scores

   1. Univariate distributions
   2. Multivariate distributions (over time)

4. Multivariate equating

5. Compare multivariate equated score to longitudinal anchor score.

   1. Univariate distributions
   2. Multivariate distributions (over time)

R Files

gen-ir.R: generates item responses and sum scores from a known growth model

univariate-equate.R: computes equated scores using univariate methods