Children in elementary school settings generally do not revise frequently or skillfully, but relatively little is known about the source of their difficulty with revision. 3 studies were conducted to investigate children's developing ability to evaluate and revise problematic texts. In the first 2 studies, fourth-grade (10 years) and sixth-grade (12 years) students were asked to evaluate 3 types of problematic texts and suggest changes to make the texts easier to understand. In the third study, children were asked whether 4 types of revisions improved the comprehensibility of problematic stories. The results showed, first, that older children detected more of the text problems; second, that when younger children spontaneously detected a text problem they were as likely as older children to revise the text adequately; third, that younger children were less able than older children to revise text problems that they had originally overlooked; and, fourth, that younger children overestimated the informativeness of several types of revisions. The results suggest that developmental differences in constructive processing contribute to children's ability to detect and revise text problems.