, Volume 79, Issue 2, pp 210–231

Analyses of Model Fit and Robustness. A New Look at the PISA Scaling Model Underlying Ranking of Countries According to Reading Literacy


DOI: 10.1007/s11336-013-9347-z

Cite this article as:
Kreiner, S. & Christensen, K.B. Psychometrika (2014) 79: 210. doi:10.1007/s11336-013-9347-z


This paper addresses methodological issues that concern the scaling model used in the international comparison of student attainment in the Programme for International Student Attainment (PISA), specifically with reference to whether PISA’s ranking of countries is confounded by model misfit and differential item functioning (DIF). To determine this, we reanalyzed the publicly accessible data on reading skills from the 2006 PISA survey. We also examined whether the ranking of countries is robust in relation to the errors of the scaling model. This was done by studying invariance across subscales, and by comparing ranks based on the scaling model and ranks based on models where some of the flaws of PISA’s scaling model are taken into account. Our analyses provide strong evidence of misfit of the PISA scaling model and very strong evidence of DIF. These findings do not support the claims that the country rankings reported by PISA are robust.

Key words

differential item functioning ranking robustness educational testing programme for international student assessment PISA Rasch models reading literacy 

Copyright information

© The Psychometric Society 2013

Authors and Affiliations

  1. 1.Department of BiostatisticsUniversity of CopenhagenCopenhagen KDenmark

Personalised recommendations