EXEMPLARY STUDIES OF INSTRUCTIONAL LEADERSHIP
Most of today's citations on instructional leadership begin with a meta-analysis conducted by Hallinger and Heck (1996,1998), and given this influence, their work is reviewed here. As a counterpoint to Hallinger and Heck's meta-analysis, we also review recent work by McREL that included a meta-analysis of principal effects on student achievement and resulted in 21 responsibilities in a model labeled balanced leadership (Miller, 2003; Waters & Grubb, 2004; Waters etal., 2003). Finally, work by Marks and Printy (2003), the 2004 Davis Award1 winners, offers a view of how the dominant use of perceptual data to measure instructional leadership can be expanded fruitfully with observational data to describe instructional leadership in a robust research design that builds on one line of conceptual work explained herein.