Writing may be an especially useful tool for improving the reading comprehension of lower performing readers and students with disabilities. However, it is reasonable to expect that students with poor writing skills in particular, may actually be less adept at using writing to improve their reading skills, and may not be able to do so without instruction. The purposes of this study were to examine (1) the extent to which writing about text (i.e., taking notes or writing an extended response) would enhance reading comprehension, (2) whether note taking was more effective than writing extended responses for improving reading comprehension for fourth grade students across three measures, and (3) whether the effects of the two writing tasks were moderated by student writing ability, indicating a minimum level of writing proficiency needed to take advantage of writing to improve reading. Students were randomly assigned to a note taking condition in which they took notes about an expository text, an extended writing condition in which they compared and contrasted ideas from the text with their own experiences, or a read and study control condition in which they studied the important ideas from the text. Minimal instruction was provided to the students in each treatment group during a single 45-minute session, primarily to ensure they understood their assigned task. The students then met for another 45-minute session, during which they were asked to read an expository passage and complete their assigned task. Students' reading comprehension was tested using three measures. Students in the combined writing treatments made significantly greater gains than students in the read and study condition on a multiple choice inference measure. No other statistically significant differences were found between the treatment groups, and no moderator effects were found. Implications for future research are framed in terms of the limitations of the study.