The purpose of this study is to translate principles of multimedia learning from college-age readers to middle grade students, when reading science texts with a supporting diagram. In this experimental study, sixth-grade students (n = 180) were randomly assigned to display conditions before reading. Each student read two explanatory sciences passages, a life-science and a physical science text. Passages were accompanied by either no illustrations (control), illustrations of the cycle with labels for each part (parts), illustrations of the cycle with labels for each major process (steps), or illustrations showing the labels for each part and each major process (parts and steps). Additionally, there were two text conditions in which half of the students read standard text (control) and half read texts with cues which indicated to students when to access the diagrams (cued). Through ANOVA analysis, in the life-science text students showed modest improvement (partial [eta][superscript 2] = 0.18) from the addition of diagrams, with the "parts diagram" and the "steps diagram" outperforming the control. In the physical science text, students did not receive benefit from the diagrams. Findings did not replicate results from college-age readers to younger readers, nor between the two texts with younger readers. These results raise concern for the application of multimedia design theory to classroom practice. (Contains 2 figures and 2 tables.)