“…For the Instructional Dimensions Study (IDS), Cooley and Leinhardt (1980) similarly used OTL measures that included how time was spent in the classroom and the overlap between the curriculum and the tests. In addition to time and content, scholars have responded to concerns about disparities within and across classrooms by expanding OTL measures to include school and classroom context variables, such as the availability of and student access to coursework and academic programs (Callahan, 2005; Cogan et al, 2001; Gamoran, 1987; Oakes, 1990), instructional quality and practices (Kurz et al, 2014; Smithson, Porter, & Blank, 1995; Stevens & Grymes, 1993; Wang, 1998), teacher expertise and experience (Aguirre-Muñoz & Boscardin, 2008; Goertz, 1994), and resources (Boykin & Noguera, 2011; Elliott, 1998; Herman & Klein, 1996; Kimura-Walsh, Yamamura, Griffin, & Allen, 2009; Oakes, 1990).…”