Instruction in early childhood special education: "seeing through a glass darkly ... knowing in part"

This article discusses what is not known about instruction of preschoolers with disabilities. Knowledge gaps exist in four areas: the content of the curriculum, the procedures used to individualize instruction, the instructional procedures designed to ensure acquisition, and the strategies used to ensure skill use or generalization. Barriers to generating such knowledge include the fragmentation that results from specialization, the inadequacy of the data base, and the lack of training in instruction and research design and analysis. Solutions include training programs for early childhood special educators in the analysis, application, and design of research in instruction and curriculum, as well as the publication of multiple replications and refinements of instructional strategies.