Pictorial mnemonic-strategy interventions for children with special needs: Illustration of a multiply randomized single-case crossover design.

An innovative single-case crossover design containing multiple forms of randomization was implemented with eight participants in seven weekly sessions, during which instruction was given in the use of two different pictorial mnemonic (memory-enhancing) strategies: one designed to improve the children's learning of the dates of various inventions and the other designed to improve the children's acquisition of unfamiliar vocabulary items. A composite randomization statistical test revealed that when compared with the children's own preferred learning methods, the mnemonic-strategy approach produced the predicted facilitation effects. At the same time, it was evident that mnemonic instruction enhanced children's performance to a greater extent on the vocabulary task than on the inventions task. In-depth examination of both individual student performance profiles and the tasks/procedures were conducted, yielding recommendations and challenges for follow-up single-case intervention research on the topic.