From 1998 to 2003, Andy Hargreaves and Ivor Goodson, along with colleagues Shawn Moore, Sonia James-Wilson, Dean Fink, and Corrie Giles, undertook a large-scale study of eight secondary schools in Ontario, Canada, and New York in the United States to investigate teachers' perceptions and experiences of educational change over 30 years spanning from the 1970s through the 1990s (Hargreaves and Goodson in Edu Admn Quart 42(1):3-41, "2006"). The "Change Over Time?" study not only provided a unique glimpse into how schools and teachers experience educational change but also demonstrated that most of what educators and scholars previously considered when looking at educational change neglected its political, historical, and longitudinal aspects. Hargreaves and Goodson highlighted five change forces that shape educational change: waves of reform, changing student demographics, teacher generations, leadership succession, and school interrelations. This article, based on work conducted in Massachusetts from 2007 to 2009 (Stone-Johnson in Enduring reform: The impact of mandated change on middle career teachers. Boston College, Chestnut Hill, "2009"; Teachers' career trajectories and work lives. Springer, Dordrecht, "2009"), elaborates upon two of these aspects, waves of reform and teacher generations, highlighting the response of the current generation of teachers in mid-career to the most recent wave of reform.