Summary
A severely retarded deaf female was taught the pluralization rule of the American Sign Language concurrently in the receptive and expressive modality. Receptive training established pointing to either one or a pair of pictures in response to the demonstration of the noun-sign with or without the S-sign. Expressive training established the usage of the correct noun-sign with or without the S-sign when presented one or two same pictures.
The training procedures were effective in establishing a generative understanding and generative usage of the manual plural sign after being trained on sufficient items in one or the other modality.
Experimental control of the training procedures was demonstrated by using the same procedures during the standard and the reversed pluralization rule.