This paper compares the professional beliefs and teaching behaviors of traditional and nontraditional/adult teacher candidates during their student teaching experience. Data for the study came from 45 elementary student teachers' structured, weekly autobiographical critical reflections written during their student teaching. Participants were predominantly white females who ranged in age from 20 to 47 years. The reflections facilitated their ability to examine their assumptions, operational theories, and focus issues, illustrating the self-evaluation dynamics of becoming critically reflective beginning teachers. Students were given structured questions that guided their weekly reflections. Analysis of the journal entries, observations of student teaching, and pre- and post-lesson interviews provided data for the study. Results indicated that there were marked differences in the developmental process of becoming a teacher. Most nontraditional students entered the experience with more self-confidence and were convinced they wanted to teach after a week in the schools, whereas most traditional candidates expressed doubts about ever becoming teachers. Despite their doubts, the traditional students were rated as highly as their nontraditional counterparts in the teacher education program's competencies and requirements. Nontraditional students viewed and interacted with cooperating teachers as peers and friends, whereas traditional candidates felt they could not overstep boundaries. Nontraditional candidates were more career focused. (Contains 25 references.) (SM)