Stimulus properties such as similarity-dissimilarity and novelty-familiarity are inherently relational and are embedded in ubiquitous stimulus contexts. Children with mental retardation and young children without mental retardation are particularly prone to failure on relational tasks such as oddity and match-to-sample (Greenfield, 1985; Soraci et al., in press). Converging evidence from a number of studies suggest that a critical factor in the performance discrepancies between these and other children is a differential sensitivity to relational information. In these studies relational characteristics of stimulus arrays were enhanced in order to facilitate performances on such relational tasks. Findings indicate the theoretical and practical significance of perceptually based interventions that induce rapid discrimination learning.