THIS EXPERIMENT WAS CONCERNED WITH ASSESSING THE RELATIONSHIPS BETWEEN SKILL IN SERIATING AND VARIOUS MEASURES YIELDED BY THE METROPOLITAN READING READINESS TEST (RRT). ANOTHER OBJECTIVE WAS TO EVALUATE THE EXTENT TO WHICH SKILL IN SERIATING IS ASSOCIATED WITH SOCIAL CLASS, SEX, AND RACE. THE AUTHORS CONSTRUCTED A SERIATION TEST WITH AN ESTIMATED MENTAL AGE RANGE OF THREE AND ONE-HALF TO SEVEN YEARS, AND ADMINISTERED IT TO KINDERGARTENERS. RESULTS INDICATED THAT--(1) SERIATION SCORES ARE STABLE, (2) SERIATION SCORES DO NOT CORRELATE MORE HIGHLY WITH MRRT (NUMBER READINESS) THAN WITH MRRT (READING READINESS), AND (3) SERIATION SCORES OF WHITES ARE HIGHER THAN THOSE OF THE NEGROES. NO SIGNIFICANT SOCIAL-CLASS DIFFERENCES WERE FOUND. SKILL IN SERIATING WAS NOT NECESSARILY ASSOCIATED WITH SEX. IT IS SUGGESTED THAT SIGNIFICANT EDUCATIONAL PROBLEMS EXIST WHEN CHILDREN ENTER KINDERGARTEN, AND THREE IMPORTANT FOLLOW-UP STEPS ARE SUGGESTED. (PH)