USING TRILINEAR PLOTS FOR NAEP STATE DATA

Understanding the distribution of achievement levels of students' perf ormance in the National Assessment of Educational Progress (NAEP) is a ided through the use of the trilinear chart. In this article, this cha rt 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. lt is suggested that th is graphical form may be useful in other contexts, as well.