ABSTRACTThis design-based research study addressed whether cognitive apprenticeships mediated by informal mentor networks can expand, deepen, and transfer knowledge with and for Learning Sciences students. Three cohorts of Learning Sciences students were invited to participate with all three represented in surveys, co-designs, and interviews, with conjecture maps produced as artifacts for personal, professional, and education agendas. Survey and interview responses demonstrate that each participant found that it was a helpful tool for collaborative learning. Theoretically grounded in situated cognition, communities of practice, and legitimate peripheral participation, the conjecture predicted improved outcomes in students' perceptions, attitudes, and beliefs with informal mentor networks to support and encourage practice and engagement. Perceptions, attitudes, and beliefs did improve with confidence in conjecture mapping, however, through iterative co-design, the focus on informal mentor networks shifted from social media due to low usage among respondents to collaborative peer tutoring. Students expressed interest in expanding their networking and mentorship opportunities. Participatory co-design with conjecture mapping significantly improved recognition as a member in a community of practice for Learning Sciences students. Keywords: situated cognition, community of practice, legitimate peripheral participation, conjecture mapping, cognitive apprenticeship, mentorship, more knowledge other (MKO)