The Effect of Teacher's Aides in the Classroom: Evidence from a Randomized Trial
通过随机试验发现，配备教师助手（无论是否有教学学位）能提高学生考试成绩，且对弱势学生的影响持续存在，其作用机制不仅是缩小班级规模，更在于分担教学责任。
Abstract Teacher's aides are used worldwide, in various school systems, although, there is no strong evidence of their impact on student outcomes. We use a randomized trial to challenge this state of evidence. We randomly allocate 105 schools to two types of treatments—aides with or without a teaching degree—compared to a control group. Both types of aides have positive impacts on test scores and the effects are persistent over time for disadvantaged students. Exploratory analyses of mechanisms suggest that a teacher's aide is not just a class-size reduction, but especially impactful when sharing instructional responsibility for the classroom.