THIS STUDY POSES THE QUESTION OF HOW TO MEASURE THE DEGREE OF INEQUALITY OF EDUCATIONAL OPPORTUNITY FOR SUBGROUPS IN SOCIETY. IT EXAMINES AND REJECTS THE DOMINANT IDEA THAT EQUAL EDUCATIONAL OPPORTUNITY IS PROVIDED BY A COMMUNITY THROUGH THE PROVISION OF FACILITIES WITH FREE AND OPEN ACCESS FOR ALL, SUBSTITUTING THE IDEA THAT IT IS THE INTENSITY WITH WHICH A SCHOOL'S RESOURCES ARE EMPLOYED IN RELATION TO THE INTENSITY OF USE OF OUTSIDE EDUCATIONAL RESOURCES (I.E., PARTICULARLY THE FAMILY) WHICH LEADS TO EQUAL OPPORTUNITIES. IT RECOGNIZES THAT BEFORE ATTENDING SCHOOL, CHILDREN HAVE VERY UNEQUAL LEARNING EXPERIENCES, WHICH MUST BE BALANCED BY MAKING SCHOOL EDUCATION MORE POWERFUL FOR THE MORE POORLY PREPARED GROUP. MEASUREMENT OF EQUALITY OF OPPORTUNITY WOULD BE ACCOMPLISHED BY (1) MEASURING THE LIST OF RESOURCES THAT MIGHT BE EFFECTIVE FOR ACHIEVEMENT FOR EACH POPULATION GROUP, (2) THROUGH REGRESSION ANALYSIS, ESTIMATING THE EFFECTIVENESS OF EACH OF THESE RESOURCES FOR A GIVEN GROUP WHICH EXPERIENCED FEWER RESOURCES THAN A GIVEN BASELINE GROUP, SUCH AS WHITES IN THE SAME REGION, AND (3) USING THESE MEASURES OF EFFECTIVENESS AND THE REGRESSION WEIGHTS FOR THE DIFFERENT SCHOOL RESOURCES TO OBTAIN A PREDICTED INCREMENT OF ACHIEVEMENT IF THE GIVEN GROUP WERE TO HAVE THE SAME RESOURCES AS THE BASELINE GROUP. THIS IS THE DIFFERENCE IN EQUALITY BETWEEN THE TWO GROUPS. (AW)