Comparing explicit to generalized requesting in an augmentative communication mode

The present study compared explicit to more generalized requesting strategies. Four adults with multiple disabilities were taught to request preferred objects by pointing to line drawings. Explicit requests were followed by access to a single specific item. Generalized requests were followed by access to any one of three related items. Percent of correct explicit and generalized requests were compared across sets of objects in a multiple-probe, single-subject design. Correct requests increased as a function of intervention, with little consistent advantage for one type of requesting strategy over the other. Analysis of error patterns suggested that while learners acquired reliable discriminations among the graphic symbols across object sets, establishing the conditional discriminations within each set proved difficult. Ecological factors for the selection of a requesting strategy and the sequencing of intervention are discussed.