MathGirls is a pedagogical-agent-based environment designed for high school girls learning introductory algebra. Since females are in general more interested in interactive computing and more positive about the social presence of pedagogical agents, the environment provides a girl-friendly social learning environment, where pedagogical agents encourage the girls to build constructive views of learning math. This study investigated the impact of agent presence on changes in the girls' math attitude, their math self-efficacy, and their learning; on the girls' choice of their agents; and, on their perceptions of agent affability. The results revealed that the girls with an agent developed a more positive attitude and increased self-efficacy significantly, compared to the girls without an agent. Both groups showed significant increase in their learning. The study also showed that the girls chose female agents significantly more than male agents as their learning partners and perceived peer-like agents as more affable than teacher-like agents. The finding confirms the instructional value of pedagogical agents functioning as a social cognitive tool [1].