A Comparison of Physical Shaping and Imitation Techniques in Teaching Signs to Individuals with Intellectual Disabilities

Abstract

The techniques of physical shaping and imitation were compared in teaching signs to 20 profoundly-severely intellectually disabled subjects and 20 moderately-mildly intellectually disabled subjects. The subjects were taught two basic signs from the Makaton vocabulary using either a physical shaping or an imitation technique. The results indicated that the moderate-mild group required fewer training trials and fewer prompts than the profound-severe group (p < .05) to learn the signs. No significant interaction between the level of disability (group) and the two treatment conditions was found. No significant difference between the two treatment conditions was found (p > .05). A failure to demonstrate any improvement in learning the signs was found in four of the profound-severe subjects in the imitation condition. All subjects in the physical shaping condition evidenced some improvement. A significant correlation was found between the subjects' performance in learning the signs and the variables of level of intellectual disability, mean length of utterance and performance on a gestural imitation probe. Although the study failed to find a difference between the two treatment conditions, physical shaping was recommended on a trial basis for individuals who are profoundly to severely disabled and who may be non-imitative. The implications for the use of correlational findings in determining prerequisite skills for entry into sign programmes are discussed. The applicability of group designs to the population of intellectual disability was questioned in light of the problems in obtaining an adequate number of subjects and the marked heterogeneity found between subjects.