Isabelle Liberman proposed in the early 1970s that in order to achieve reading mastery in an alphabetic writing system, a would-be reader must become aware that words are segmentable into sequences of phonemes. She noted that the ability to analyze the internal structure of the word into its phonemic constituents is an intellectual achievement that is distinct from the universal human ability to learn and use the spoken language -- an ability that, unlike reading, develops in every normal child. Convinced that phonemic awareness does not come about as an automatic consequence of language acquisition, Liberman and her colleagues proposed that the lack of one-to-one correspondence between phoneme segments and acoustic structure makes it difficult for a young child to become aware of the phoneme and thus difficult to grasp the alphabetic principle.
Through the efforts of researchers throughout the world, the central role of phonological awareness in learning to read and write in an alphabetic system is becoming widely recognized. Though a consensus has developed about the importance of phonological awareness, there have been differences in interpreting its role in the reading process. Some have seen it chiefly as a precursor to reading and others have seen it primarily as a concomitant. Accordingly, it has become vitally important to discover the developmental course of phonological awareness and to determine how conscious representations