This paper explores Fred Genesee's Classroom Based Assessment (CBA) as an alternative model for assessing instruction as it affects students' learning in an immersion program. CBA collects information on language while instruction and other activities are taking place, allowing teachers the flexibility to alter teaching strategies to be more responsive to students' learning. Conventional assessment primarily measures learning via written tests. Its perspective defines learning as a product achieved by the individual student yet ignores the process involved in teaching and learning. The study examines the role of the teacher in the assessment process and proposes that CBA considers not only instruction as it affects learning but the quality of teaching as well. Five critical taching skills (knowledge, pedagogy, observational, interpersonal, instructional) during an instructional activity are discussed as they impact on student achievement. The placement of teachers at the center of what is called the Teacher Classroom-Based Assessment (TCBA) process is recommended that predicts, explains, and modifies the links between teaching and learning and helps to draw conclusions and make recommendations for instruction, inclusive of teaching. (Contains 25 references.) (Author/NAV)