Children with learning problems require early intervention. If it is evidence based and implemented with integrity and intensity, it will accelerate the academic progress of many students. This is the hope and expectation of the many supporters of responsiveness-to-intervention (RTI). A minority of children, however, will not respond sufficiently to such intervention because of learning disorders like specific learning disabilities (SLD). Some RTI models do not include research-backed methods to identify these children, nor do RTI practitioners often produce the data necessary to develop individualized instruction for them. The authors suggest practitioners go beyond typical RTI assessment data documenting responsiveness/ unresponsiveness to conduct comprehensive evaluations of these most difficult-to-teach students and to include in their evaluations carefully chosen cognitive measures. This special issue presents the work of teams of researchers, which suggests that cognitive and neuropsychological assessments can provide information to further understand SLD, which in turn can guide development of promising interventions.