Contrasts a fixed-rate presentation list with one in which half the items in a single list were presented at a fast rate and half at a slow rate during paired associative learning with 24 children (aged 8 to 22 years) who were diagnosed with having an attention deficit disorder. (HOD)

Two studies involving three adolescents with severe emotional disturbance/behavior disorders and learning difficulties examined effects of problem difficulty and reinforcer quality upon time allocated to two sets of arithmetic problems. Results have implications for understanding the effects of problem difficulty and reinforcer quality on behavior…