Toward a technology of generalization: how many exemplars are sufficient?

This descriptive study examined the number of minimal-word-pair exemplars necessary for 19 phonologically impaired children to meet a generalization criterion. For 59% of the test cases, three exemplars were sufficient for generalization to occur. Five exemplars were sufficient in 21% of the test cases, and it was necessary to teach 10 different exemplars in 14% of the test cases. In 7% of the test cases, generalization did not occur despite treatment on 10 exemplars. Although generalization usually occurred following treatment using a small number of exemplars, there was substantial variability across individual subjects. There was no apparent relationship between specific sounds and the likelihood of generalization; however, the data from some children suggested that treatment on one sound enhances learning of subsequent sounds. The theoretical and clinical implications of these findings are discussed.