

Examining the performance of the trifactor model for multiple raters
Using simulations, this study examined the “trifactor model,” a recent model developed to address rater disagreement.
By: James Soland, Megan Kuhfeld
Topics: Measurement & scaling


Achievement growth in K-8 Catholic schools using NWEA data
Using a national sample of kindergarten to eighth grade students from Catholic and public schools who took MAP Growth assessments, we examine achievement growth over time between sectors.
By: Julie Dallavis, Megan Kuhfeld, Beth Tarasawa, Stephen Ponisciak
Topics: Early learning, Middle school


BFpack: Flexible Bayes factor testing of scientific theories in R
In this paper we present a new R package called BFpack that contains functions for Bayes factor hypothesis testing for the many common testing problems. The software includes novel tools for (i) Bayesian exploratory testing (e.g., zero vs positive vs negative effects), (ii) Bayesian confirmatory testing (competing hypotheses with equality and/or order constraints), (iii) common statistical analyses, such as linear regression, generalized linear models, (multivariate) analysis of (co)variance, correlation analysis, and random intercept models, (iv) using default priors, and (v) while allowing data to contain missing observations that are missing at random.
By: Joris Mulder, Donald Williams, Xin Gu, Andrew Tomarken, Florian Böing-Messing, Anton Olsson-Collentine, Marlyne Meijerink-Bosman, Janosch Menke, Robbie van Aert, Jean-Paul Fox, Herbert Hoijtink, Yves Rosseel, Eric-Jan Wagenmakers, Caspar van Lissa
Topics: Measurement & scaling


Using data from the Applied Problems subtest of the Woodcock-Johnson Tests of Achievement administered to 1,364 children from the National Institute of Child Health and Human Development (NICHD) Study of Early Childcare and Youth Development (SECCYD), this study measures children’s mastery of three numeric competencies (counting, concrete representational arithmetic and abstract arithmetic operations) at 54 months of age.
By: Pamela Davis-Kean, Thurston Domina, Megan Kuhfeld, Alexa Ellis, Elizabeth Gershoff
Topics: College & career readiness, Early learning, Math & STEM


This research introduces a novel approach, using the Bayes factor, wherein a researcher can directly test for homogeneous within-person variance in hierarchical models. Additionally, we introduce a membership model that allows for classifying which (and how many) individuals belong to the common variance model.
By: Donald Williams, Stephen Martin, Phillipe Rast
Topics: Measurement & scaling


MAP Growth linking studies: Intended uses, methodology, and recent studies
This document presents the intended uses and methodology of the MAP Growth linking studies, a description of the results provided in the linking study reports, and a summary of the recent linking studies conducted by NWEA to incorporate the new 2020 norms.
By: Ann Hu
Products: MAP Growth


An investigation of item parameter invariance using focused calibration samples for MAP Growth
Two studies were conducted to evaluate whether the existing MAP Growth item parameter estimates are invariant across different calibration samples.
By: Wei He
Products: MAP Growth
Topics: Computer adaptive testing