The purpose of the eight studies reported in this paper was two-fold: to identify some of the relationships that exist between the unique properties of diagrams and various aspects of cognitive processes and learning, and, subsequently, to derive principles from these relationships that would direct the design and use of diagrams in the classroom.…

The inclusion of "purpose questions" before passages in reading comprehension tests is evaluated in light of recent research related to schema theory and adjunct questions. While research supports the use of purpose questions, gaps and weaknesses in the available data exist. Suggestions for further study are provided. (Author/LMO)