Drawing on a sociocultural view of learning as acculturation into the distinct social language of academic communities, this study reports the developmental impacts of an intervention program designed to prepare students from a comprehensive urban high school for the rigors of college reading and writing. Statistical analysis of students' pre-, mid- and post-test performances on a university writing placement exam demonstrates significant growth. Qualitative analysis of their formal and informal writing employing three semantic differential scales designed to measure reciprocity, indexicality, and intertextuality, however, illuminates how struggles to negotiate the terms of participation in an academic community of practice and students' conceptual orientations toward written texts limited the extent to which students could fully master the social language of academic argumentation. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]