The motivation to explore the use of portfolios in the Bank Street College (New York) program of teacher education emerged in response to a range of serious concerns about how the program met the needs of today's teacher and classrooms. The portfolio process as implemented at Bank Street is designed to be learner centered. It asks students to: (1) identify and discuss the artifacts that they find most significant in their personal and professional development; (2) identify connections between and among artifacts; (3) reflect upon these connections in order to identify a unifying theme; (4) examine artifacts and themes from both personal and theoretical perspectives; and (5) participate in public presentations of the portfolio. The completed portfolio includes artifacts such as audio tapes, videotapes, picture collages, and various writing genres; one- or two-page captions to accompany each artifact; and an introductory framing statement. The work of each student is supported by individual meetings between students and faculty portfolio mentors and a series of required monthly meetings that provide opportunities for peer mentoring. Data for a study of the process were gathered from 47 Master's degree students who chose to take part in a pilot project using portfolios as a culminating project. Study findings support the assumption that portfolios have the potential to be a generative and transformative pedagogical tool, involving students in the process of setting and meeting goals that bridge personal and professional funds of knowledge. The data also suggest, however, that constraints to achieving this potential emerge from the prior experiences of both faculty and students, the structures of institutions of learning, and the pervasive influence of a traditional authority relationship. (Contains 49 references.) (ND)