THIS MANUAL DESCRIBES MEASURES USED IN "THE COGNITIVE ENVIRONMENTS OF URBAN PRE-SCHOOL CHILDREN" PROJECT AT THE UNIVERSITY OF CHICAGO. THE SAMPLE FOR THE STUDY CONSISTED OF 163 NEGRO MOTHER-CHILD PAIRS SELECTED FROM 3 SOCIOECONOMIC CLASSES BASED ON THE FATHER'S OCCUPATION AND THE PARENTS' EDUCATION. A FOURTH GROUP INCLUDED FATHER-ABSENT FAMILIES. THE MOTHERS WERE INTERVIEWED AT HOME AND THE MOTHERS AND CHILDREN WERE TESTED AT THE UNIVERSITY OF CHICAGO WHEN THE CHILDREN WERE 4 YEARS OLD. FOLLOW-UP DATA WERE OBTAINED WHEN THE CHILDREN WERE 6 AND AGAIN WHEN THEY WERE 7. THE BLOCK SORTING TASK WAS THE SECOND OF 3 MOTHER-CHILD INTERACTION TASKS GIVEN DURING THE SECOND UNIVERSITY TESTING SESSION. THE OTHER 2 ARE DESCRIBED IN PS 000 486 AND PS 000 489. EIGHT BLOCKS HAVING 4 DISTINGUISHABLE ATTRIBUTES--HEIGHT, SHAPE, COLOR, AND A MARK--WERE SORTED INTO 4 GROUPS USING PAIRS OF ATTRIBUTES. EACH MOTHER WAS SHOWN THE BASIS OF THE GROUPINGS SO THAT ADDITIONAL BLOCKS COULD BE CORRECTLY ADDED. SHE WAS THEN ASKED TO TEACH HER CHILD HOW TO ADD EXTRA BLOCKS TO THE GROUPS. HER INSTRUCTION WAS OBSERVED AS DESCRIBED IN PS 000 491 AND SCORED AS DESCRIBED IN PS 000 488. THE CHILD WAS TESTED WITH 2 NEW BLOCKS. SCORING WAS ON A 6-POINT SCALE, A POINT BEING GIVEN FOR EACH CORRECT PLACEMENT AND FOR EACH ATTRIBUTE MENTIONED AS A REASON FOR PLACEMENT. THE COMPLETE SET OF PROJECT MANUALS COMPRISES PS 000 475 THROUGH PS 000 492. (DR)