Responding to student writers and their work is a staple of composition instruction, and there are numerous guides that offer educators advice on response strategies. However, such guides are often based on untested theories or assumptions about the effectiveness of those strategies, with little data-driven evidence of whether they work as hoped or intended. Furthermore, much research of response and/or revision is conducted in language-learning contexts or focus only on response provided by teachers and/or in-class peers. This project therefore presents a mixed-methods analysis of teachers' and writing consultants' response strategies and college writers' revision activity in composition-learning contexts at Saint Louis University to discover what and/or whose comments result in revision attempts. Surveys, rough drafts (with responder comments), and final drafts were collected and analyzed. Findings revealed that responders fell into three categories: instructors (classroom composition pedagogy/experience only), consultants (writing center pedagogy/experience only), or cross-trained (both forms of pedagogy/experience). These differences in training correspond with differences in response strategies. Additionally, writers acted on comments at different rates, with instructors' comments resulting in the lowest rates of attempt (42% on average) with consultants and cross-trained responders' comments resulting in much higher rates (63% and 61% respectively). These and other findings indicate that writing center pedagogy has considerable influence on writers' revision activity. Most importantly, though, student writers are still developing response and revision literacy, and current response and pedagogical practices are not always explicitly directed at improving those literacies. Teachers, consultants, and writing program/writing center administrators can improve student writers' understanding of response and revision through targeted interventions, especially ones that exercise metaresponse: engaging writers in thinking about and responding to response. [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 (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]