This longitudinal study compared the longterm effects of beginning reading instruction in traditional orthography (TO) and the initial teaching alphabet (i.t.a.) on two pupil populations comparable in intelligence, socioeconomic status, and preschool experience. Teacher and school factors were rigorously controlled. A continuous comparison of results in the first through sixth grades on standardized measures of reading achievement was supplemented by studies of characteristics of writing and spelling behaviors and creativity measures to determine longitudinal effects of the differentiated beginning. It was found that the i.t.a. pupils continuously showed better abilities in word discrimination, word knowledge, spelling, and creative use of words than did the TO pupils. Additional data also indicated (1) that twice as many TO pupils received remedial reading as did i.t.a. pupils during this period and (2) that while the TO pupils needed help on word recognition and comprehension, the i.t.a. pupils needed help only on comprehension. It was concluded that compared to the use of TO, the use of i.t.a. had a significantly more beneficial and lasting effect in developing the characteristics which combine to produce a higher success rate among children. Tables are included. (AW)