This document presents reports of three studies focused on cooperative pedagogical strategies. The first concerns individualistic and cooperative goal structures in high school mathematics achievement. Two general mathematics classes were taught a unit on percents, one with a cooperative and the other an individualistic goal structure. The cooperatively goal structured classroom demonstrated significantly higher posttest achievement scores than the individualistic group. The second paper is on cooperative learning in ninth grade remedial mathematics classes. One class used a modified team approach, while the other used an individualistic goal structure including class lecture, individual seatwork, and homework. Significant increase in mean post-test scores was obtained, suggesting that cooperative strategies are effective. The third paper is written on cooperative versus competitive reward-structured secondary science classroom achievement. Two biology classes were taught an identical unit, one in an individually competitive structure and one using a cooperative structure called the group-investigation model. No significant differences were found. (MNS)