In writing classrooms, peer review has been shown to have numerous practical and cognitive benefits. However, little research has been done that examines how different types of peer feedback motivate adolescent students and the effects that different types of feedback have on writing quality. While the literature has indicated that peers give each other much more positive feedback than their teachers do, the research has yielded conflicting findings on whether comments about strengths or comments about weaknesses are more helpful. For this study high school seniors in an AP English Language and Composition class were randomly assigned to one of three treatments: a group directed only to provide comments about the strengths in the writing of their peers, a second group directed only to provide comments about weaknesses, and a "business as usual" group who were directed to provide helpful feedback (typically a mix of strength and weaknesses comments). There were no treatment group differences in students' writing quality and motivation (attributions, belongingness, and sociocognitive conflict regulation). However, there were clear indicators that suggest students saw statistically significant differences in how helpful some types of comments were perceived to be. Implications for the theory and practice of peer-based feedback in writing instruction are discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]