This paper explores the scope of "failure" in the period of practice immediately prior to teacher certification, by examining personal experiences of 25 preservice teachers who "failed" or hovered in failure-like circumstances. Indicators of failure included poor interpersonal skills, lack of primary focus on students, lack of commitment and attention to lesson preparation, lack of enthusiasm for and interpretation of content knowledge, poor classroom management, and poor general preparation for the school placement. The paper concludes that the underlying assumptions and structure of student/practice teaching should be reconceptualized, as for many individuals its traditional format, scope, sequence, and emphasis proves problematic and sometimes entirely mis-educative. Other implications for teacher education include the need to establish more pertinent selection criteria for prospective teachers, to offer preservice teachers extensive and continuing counseling and guidance, to provide greater levels of care and attention to student/practice teaching placements, to provide increased levels of effective supervision and facilitation of their practice, to provide opportunities for substantial remediation, and to provide exit counseling and vocational guidance when necessary. A taxonomy of "failure" factors is presented. (Contains 57 references.) (JDD)