THE ASSUMPTION THAT READING DISABILITY CAN RESULT FROM A GAP BETWEEN THE DEVELOPMENTAL MATURITY OF CHILDREN AND THE DEMANDS OF A BEGINNING READING PROGRAM CARRIES WITH IT THE PROBLEM OF ASSESSING DEVELOPMENTAL STATUS. A LONGITUDINAL STUDY CONDUCTED TO DERIVE A METHOD FOR IDENTIFYING SIGNS OF IMMATURITY RELATED TO LATER READING DIFFICULTIES USED 102 DIFFERENT DESIGNS FROM FIVE KNOWN TESTS OF PERCEPTUAL-MOTOR READINESS WITH 2,000 CHILDREN IN 72 KINDERGARTEN TO GRADE-4 CLASSES. THE CHILDREN'S REPRODUCTIONS WERE ANALYZED IN TERMS OF "PLANS" WHICH ARE THE VARIOUS PERCEPTUAL UNITS EACH CHILD USED IN ANALYZING AND ORGANIZING A WHOLE DESIGN BEFORE COPYING IT. DESIGNS TOO COMPLEX FOR THE CHILD'S LEVEL OF MATURITY YIELDED PLANS WHICH WERE NOT SUFFICIENTLY ARTICULATED, PLANS WHICH WERE TOO GLOBAL, AND THOSE IN WHICH PARTS WERE NOT WELL DIFFERENTIATED OR IN WHICH SPATIAL RELATIONS WERE DISTORTED. IMMATURITY IN PERCEPTUAL-MOTOR FUNCTIONING IN KINDERGARTEN AND GRADE 1 IS PART OF THE NORMAL DEVELOPMENTAL PATTERN, AND MATURITY IS DEVELOPED THROUGH TACTUAL, VISUAL, AND MANIPULATORY EXPERIENCES. DETAILED FINDINGS, EXAMPLES OF THE CHILDREN'S REPRODUCTIONS, AND A BIBLIOGRAPHY ARE INCLUDED IN THIS REPORT. THIS PAPER APPEARS IN THE "CLAREMONT READING CONFERENCE, THIRTIETH YEARBOOK," CLAREMONT GRADUATE SCHOOL CURRICULUM LABORATORY, CLAREMONT, CALIFORNIA. (NS)