Abstract analogies and abstracted grammars: Comments on Reber (1989) and Mathews et al. (1989).

Reber (1969, 1989a) and Mathews et al. (1989), in experiments on learning artificial grammars, reported good transfer to letter strings consisting of letters not used in the training stimuli, provided that the same grammar generated both training and transfer strings. They concluded from this that the transfer predominantly relies on abstract knowledge. An experiment is reported that shows much of the transfer to changed letter-set strings is due to abstract similarity between test strings and specific training stimuli (i.e., a string such as MXVVVM could be seen as similar to BDCCCB without implying that regularities common to a large number of training items had been abstracted)