Subject descriptions and single-subject research.

In this manuscript, we respond to the minimum standards for describing research subjects as proposed by the Council for Learning Disabilities (CLD) Research Committee. Three issues are raised about the standards: (a) whether justification exists for the recommended standards, (b) whether a relationship exists between the description of subjects and the probability of replication, and (c) whether all types of research require the same subject description standards. These issues are discussed, and three recommendations to investigators who use single-subject research designs are made: (1) Describe variables that control subjects' performance in baseline conditions and the contexts of that performance, (2) identify subject selection criteria, and (3) report status variables as recommended by the CLD Research Committee.

Teaching idiom comprehension to children with mental retardation.

This study examined the effectiveness of a training program designed to teach children with mild mental retardation the meaning of 12 idiomatic phrases, such as "to hit the sack." Four 9-year-old children participated in the training. A multiple baseline design across subjects and across three sets of idioms was implemented. Training consisted of presenting both literal and idiomatic contexts in the form of story narratives, and asking the children to explain the outcome of the story and to select one picture from an array of four that represented the outcome. All children demonstrated learning, although 1 child required review procedures to facilitate maintenance. Children were able to generalize their receptive learning to an expressive task with varying levels of success. All children demonstrated an ability to understand the learned idioms when presented in unfamiliar contexts.

Comparison of idiom comprehension of normal children and children with mental retardation.

This study compared the comprehension of 20 idioms of normal children with children exhibiting mild mental retardation. Sixty-six children comprised three groups: normal 9-year-olds, 9-year-old children with mild mental retardation, and younger normal children matched with the mentally retarded children by receptive vocabulary age. The assessment included both literal and idiomatic contexts with accompanying picture stimuli. The three groups demonstrated high accuracy with the literal contexts. On the idiomatic contexts, the normal children comprehended significantly more idioms than the children with mental retardation, and the mentally retarded children performed significantly better than the younger normal children.

Observational learning of comprehension monitoring skills in children who exhibit mental retardation.

An observational learning paradigm was used to instruct 5 children with mild or moderate mental retardation to monitor their comprehension of inadequate instructions. Instructions were inadequate because of an interfering signal, an unfamiliar word, excessive length, or an unfamiliar idiomatic phase. Subjects' peers served as models during the training. A multiple baseline design across subjects and across instruction types was employed. All subjects learned to request clarification of the first three inadequate instructions; however, none of the children learned to request clarification of idiomatic phrases. Although all children eventually demonstrated observational learning, three children required feedback from the trainer before they began to request clarification for one or two of the instruction types. Two children generalized their requesting behavior to the interfering signal message type, suggesting that generalization may be likely to occur between similar message types. During posttesting all children generalized their requesting behavior when presented with two unfamiliar message types, sometimes using new question forms. Four of the 5 children also generalized their requesting behavior in sessions with their teachers 5-10 weeks later.

Effects of imitation on language comprehension and transfer to production in children with mental retardation.

This study investigated the effects of verbal imitation on the comprehension of novel object-location responses and subsequent transfer of these responses to production. A matrix training procedure was used to teach 2 children with moderate mental retardation syntactic rules for combining known and unknown words into two-word utterances. An alternating treatments design was used with two conditions: receptive teaching with imitation of the target phrase and no imitation of the phrase. Findings suggested that the use of imitation facilitated both generalized receptive learning and transfer to production in both subjects.