Studied how two components of phonemic awareness, recognition of phoneme identity across words and recognition of phonemic segmentation within words, influence acquisition of the alphabetic principle in preliterate children. Evidence favored training in phoneme identity over segmentation as a component of initial reading instruction because it was easier to implement and its relationship to alphabetic insight was stronger. The study also found that identity can be equally easily taught using word-initial and word-final phonemes, a phoneme in a consonant cluster does not present special problems, vowels are as amenable to training as consonants, and stops are more problematic than continuants. Once alphabetic insight is established for some letters, following identity and letter-sound instruction, it generalizes to other letters without the need for further phonemic awareness training. Implications for the initial reading curriculum are discussed.