The purpose of two experiments was to contrast instructions to generate drawings with two text-focused strategies--main idea selection (Exp. 1) and summarization (Exp. 2)--and to examine whether these strategies could help students learn from a chemistry science text. Both experiments followed a 2 x 2 design, with drawing strategy instructions (yes vs. no) and main idea/summarization strategy instructions (yes vs. no) as experimental factors. The main dependent variable was science text comprehension, measured by a multiple-select test and a transfer test. Participants were 90 (Exp. 1) and 71 (Exp. 2) students (grade 10). The results of both experiments showed positive effects of the drawing strategy instructions and negative effects of the text-focused strategy instructions without interactions. These results are consistent with the mental model approach to comprehension, showing advantages of drawing activity in fostering science text comprehension. (Contains 3 figures and 4 tables.)