Interest in educational change has continued to grow over the past three decades (Fullan, 1982; Tyack & Cuban, 1995). One focus has been the challenge of implementing sustainable reforms, particularly in secondary schools, which have traditionally been resistant to change (Goodson, 1983; Hargreaves, 2003; Louis & Miles, 1990; McLaughlin & Talbert, 2001). Another has been the role of teachers in implementing, sustaining and also resisting change (Fullan, 1993; Hargreaves, 1994; Kennedy, 2005; Little, 1996). In spite of challenges--and arguably lack of success--wave after wave of reform has attempted to introduce lasting change in schools (Sarason, 1990). No Child Left Behind (NCLB) (U.S. Department of Education, 2002) represents the latest wave of reform. This wave requires a relentless focus on achievement and improvement. The impact of NCLB is felt at the state level, where high-stakes, standardized tests are given annually as a means to measure progress (U.S. Department of Education, 2002). In Massachusetts, the test is the Massachusetts Comprehensive Assessment System (MCAS). While the effects of mandated change are undoubtedly felt at all levels, it is teachers in mid-career for whom the stakes might be highest. Will reform work successfully stimulate and support them, or will it feel like an additional and unwanted burden on the their already full schedules? My dissertation thus explores the following question: * What are the effects of contemporary high-stakes mandated reform on the change commitments and capacities of middle career teachers? Related to this broad question, I explore the in-school conditions and generational factors that influence these change commitments and capacities. The surprising findings revealed that most teachers, representing both high and low performing schools in urban and suburban districts, felt that the MCAS in particular and the standards movement in general offer a neutral to positive opportunity for teachers to assess their students and to hone their curricular and teaching strategies. This statement holds true for the quantitative data as well; teachers generally appear to feel more control and influence over their work than in the recent past.