The effects of stimulus and response abstractness and similarity were investigated in children's paired-associate learning of graphemephoneme correspondences. In the first experiment, stimulus and response abstractness were investigated in a factorial design. The results indicated that the major source of learning difficulty was response abstractness. In a second study, stimulus and response similarity were also varied factorially. Neither factor had a significant effect on the number of correct responses. The implications of the results for teaching grapheme-phoneme correspondences were discussed.