A study examined the developmental shifts in the importance of linguistic components of words to single word decoding. Subjects, 1200 children ages 6-7, 8-9, and 10-12.5 years who were the normative sample of the Kaufman Assessment Battery for Children (K-ABC), were tested using a word recognition test, the Reading Decoding Subtest of the K-ABC. Each word was decomposed into nine structural components important to linguistic information: number of phonemes, graphemes, syllables, morphemes, consonant digraphs, vowel digraphs, r-controlled vowels, consonant blends, and silent markers. Results indicated that: (1) for all three age levels, phonemes, graphemes, and syllables were so highly correlated and correlated so similarly to success in decoding that only phonemes were used; (2) for all three age levels, within subject regression coefficients of the seven variables on right-wrong score exhibited the same direction of regression but relative importance varied; and (3) phonemic complexity accounted for the highest amount of variance at each level, with other variables shifting across age in a pattern consistent with a stage development model for reading. Findings suggest questioning the concept of a true automaticity in reading. (One table of data is included; 18 references are attached.) (Author/RS)