THE EMPIRICAL STUDY OF SOCIAL NORMS HAS BEEN HAMPERED BY A LACK OF STANDARDIZED QUANTITATIVE MEASURES AND CRITERIA FOR THE INTERPRETATION OF RESEARCH DATA. TWO CRITERIA ARE SUGGESTED, BOTH DERIVED FROM THE MODAL PROPORTION OF RESPONSES. THE FIRST CRITERION SIGNIFIES A MODAL PROPORTION LARGE ENOUGH TO REPRESENT A POPULATION NORM. THE SECOND CRITERION IS LESS STRINGENT AND INDICATES THE PRESENCE OF A PROMINENT NORM. MINORITY NORMS AND PLURALITY NORMS ARE ALSO QUANTITATIVELY DEFINED. THE PROPOSED PROCEDURE INVOLVES A SUCCESSION OF COMPUTATIONS APPLIED TO RESPONSES TO AN ATTITUDINAL OR BEHAVIORAL QUESTION FROM A REPRESENTATIVE SAMPLE SO AS TO DETERMINE THE DEGREE TO WHICH A SOCIAL NORM IS EVIDENCED IN THE RESPONSES. THE COMPUTATIONS WILL INDICATE THE EXISTENCE OF A REPRESENTATIVE NORM (EVIDENCE OF A CLEAR, ESTABLISHED NORM), A PROMINENT NORM (PROMINENT BUT NOT REPRESENTATIVE), A PLURALITY NORM (NORM HELD BY SLIGHTLY MORE THAN HALF THE RESPONDENTS), AND A MINORITY NORM (NORM HELD BY A SIGNIFICANT MINORITY OF RESPONDENTS). THE COMPUTATION PROCESS IS APPLIED TO TWO SURVEYS. MATHEMATICAL EQUATIONS, TABULAR DATA, NOTES, AND REFERENCES (CA.20) ARE INCLUDED.