SOME MULTIVARIATE DISPLAYS FOR NAEP RESULTS

The principal goal of graphic display is to ease access to complex inf ormation. Simple univariate displays are easy to understand but usuall y do not have the capability to transmit accurately the often complex structure of multivariate data. Multivariate displays were specially d esigned for exactly this purpose. The National Assessment of Education al Progress (NAEP) generates data of a multivariate richness and compl exity that defies accurate univariate transmission. The broad use and understanding of the information NAEP provides can be aided through th e use of more suitable and evocative data displays. In this article, w e demonstrate the limitations of univariate displays and suggest some multivariate displays that may enable us to understand, and thence com municate, what is contained in NAEP more fully.