System Identification of Learning Disabled Children: Implications for Research Sampling

Abstract

System identification of learning disabled (LD) children is discussed in terms of its effect on sampling for research purposes. The identification process that takes place in most schools involves numerous procedures which allow for variability in the way in which children are identified for learning disability services and end up serving as populations for research efforts. The sources of variability are discussed along with recent research supporting the existence of such variability. Variation sources include teacher bias, peer tolerance, socioeconomic background characteristics, prereferral efforts, assessment variability, uncertainty in definitions and criteria for diagnosis, and placement decision-making variability. Implications for sampling system-identified learning disabled populations are discussed in terms of problems related to the use and interpretation of group designs and description of samples. Suggestions are given for reading and interpreting research given existing sampling problems.