In recent years, the focus of assessment practices has shifted from assessment of instruction to assessment for instruction. A factor in the changing assessment practices is the emergence of Response to Intervention (RTI) as a support structure for all students. RTI was fi rst formally included in federal education policy in the 2001 No Child Left Behind (NCLB) Act (No Child Left Behind [NCLB], 2001). NCLB was an update of the Elementary and Secondary Education Act (ESEA) that provides funding for support programs in U.S. schools. Additional language about RTI was included in the 2004 reauthorization of the Individuals with Disabilities Education Act (IDEIA; Individuals with Disabilities Education Improvement Act, 2004). While RTI’s fi rst formal mention was in the 21st century, it has roots that go back many more years.