Research designed to identify the instructional and ecological conditions that foster the development of literacy skills in children with reading disabilities reflects a complex, multivariate enterprise. In essence, such research must be able to ultimately identify the teacher characteristics and instructional components that are critical for individual children and the interrelationships among these components. The intensity and duration of instruction will differ according to the severity of deficits in either single- or multiple-component reading processes. Moreover, training in any one component may not be sufficient to produce automatic improvements in other reading skills. This article identifies a number of conceptual and methodological issues that should be considered when conducting and interpreting reading intervention research.