The edTPA, a nationally available performance assessment for teacher candidates, has recently been developed and implemented in teacher education programs across the United States. Advocates make arguments for the need for such an assessment while critics of standardized performance assessments point out the dangers of standardization. This article takes a step back from the arguments in support of or in opposition to the assessment and asks fundamentally what the underlying conception of teaching of the edTPA is. After examining conceptions of teaching articulated by scholars such as Nathanial Gage, Larry Cuban, Lee Shulman, Paulo Freire, and bell hooks, this article argues that the underlying conception of teaching of the edTPA is one of professional practice, not only at the individual level but also at the level of teaching as a collective enterprise. The conception of teaching argument is also connected to discussions of the validity arguments for the edTPA with specific attention to face validity, content validity, and construct validity.