We investigate how technologies that automatically score student written essays and assign individualized guidance can support student writing and revision in science. We used the automated scoring tools to assign guidance for student written essays in an online science unit, and studied how students revised their essays based on the guidance and what kinds of revisions promoted science learning. Four teachers and their 470 students participated. Findings suggest integrating ideas when revising a science essay is a more successful revision strategy than adding new, but disconnected, ideas. We discuss how automated scoring and guidance tools can be refined to promote integrating ideas.