In this lead article three emergent problems in the analysis of cross-national survey data are raised in a context of 40 years of research and development in a field where persistent problems have arisen and where scholars across the world have sought solutions. Anomalous results have been found from secondary data analyses that would appear to stem from the procedures that have been employed during the past 15 years for the estimation of educational achievement. These estimation procedures are briefly explained and their relationships to the observed anomalies are discussed. The article concludes with a challenge to the use of Bayesian estimation procedure, while possibly appropriate for the estimation of population parameters would appear to be inadequate for modelling scores that are used in secondary data analyses. Consequently, an alternative approach should be sought to provide data on the performance of individual students, if a clearer and more coherent understanding of educational processes is to be achieved through cross-national survey research. (Contains 2 footnotes, 1 table and 4 figures.)