Using Trilinear Plots for NAEP State Data

Abstract

Understanding the distribution of achievement levels of students’ performance in the National Assessment of Educational Progress (NAEP) is aided through the use of the trilinear chart. In this article, this chart is described and its use illustrated with data from the 1992 state NAEP mathematics assessment. It is shown that one can see readily the trends in performance for different demographic groups for all of the 44 participating jurisdictions simultaneously. It is suggested that this graphical form may be useful in other contexts, as well.