Instructors and researchers often consider peer review an integral part of the writing process, providing myriad benefits for both writers and reviewers. Few empirical studies, however, directly address the relationship between specific methodological changes and peer review effectiveness, especially outside the composition classroom. To supplement these studies, this paper compares types of student commentary received between a control and guided rubric in an introductory biology course in order to determine if guided questions augment the amount of "feedforward" responses, questions and suggestions that consider the next draft and are reported to be more beneficial than feedback. Results indicate that guided rubrics significantly increase "feedfoward" observations and reduce less useful categories of feedback, such as problem detection and meanness. Differences between rubrics, however, had limited influence on student attitudes post-peer review. Consequently, potential strategies for further improving student ratings and keeping mean commentary at a minimum are discussed.