This quasi-experimental study compared academic learning in project-centered instruction with group projects, project-centered instruction with individual projects, and teacher-led instruction. A repeated measures pre and posttest design was used to measure the change in Social Studies content learning in sixth grade students for three different instructional units taught with each of the three teaching approaches. ANOVA was used to compare pre and posttest scores. All three teaching approaches were compared, and the two project-centered conditions were compared to identify possible learning differences related to cooperative learning. Students in the group project condition demonstrated the greatest gains in content learning. Students in the individual project condition demonstrated the smallest gains from pre to posttest. The results of this study suggest that for most students the opportunity to engage in discourse about content through group work, or via teacher talk and class discussion enhances academic learning to a greater degree than individual study and research for middle school students. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]