After reviewing a small body of literature on the assessment practices of American orchestra directors, this chapter quickly shifts attention to conducting original research. It describes a descriptive survey study with American String Teachers Association (ASTA) members (N = 416) that found performance-based assessments were the most frequently used form of formal assessment to evaluate technique, musicianship skills, creative musicianship, and ensemble skills. Music literacy was nearly equally split between performance-based and written assessments, while evaluation of music and musical performances and historical and cultural elements tended toward written assessments and verbal feedback. Creative musicianship and historical/cultural elements were the top two nonassessed areas, but were still assessed by the vast majority of teachers. Interviews with five string teachers demonstrate that the research participants emphasized performing/playing assessments, focused on student learning/improvement, acknowledged the role of the school district/administration and benefited from its support, and recognized the value in aligning assessment to standards/curriculum.