IN THE QUANTITATIVE PARADIGM, THE RESEARCHER IS MOST OFTEN CONCERNED WITH (1) DISCOVERING, VERIFYING, OR IDENTIFYING CAUSAL RELATIONSHIPS AMONG CONCEPTS THAT DERIVE FROM THEORETICAL SCHEME; (2) ASSIGNING SUBJECTS AND USING SAMPLING TECHNIQUES TO MINIMIZE INTERVENING VARIABLES THAT COULD AFFECT RESEARCH RESULTS; (3) USING A CONTROL GROUP TO EVALUATE THE EFFECT OF NO INTERVENTION; AND (4) ESTABLISHING PROCEDURES FOR DATA COLLECTION AND STATISTICAL ANALYSIS. IN THE QUALITATIVE PARADIGM, RESEARCHERS ARE AWARE OF EXISTING THEORETICAL FRAMEWORKS OR EXPLANATIONS FOR THE PHENOMENON UNDER STUDY BUT PREFER THE THEORY TO EMERGE FROM THE DATA. THEY ATTEMPT TO FIND OUT WHAT EXPLANATORY SCHEMES ARE USED BY THE SUBJECTS UNDER STUDY TO MAKE SENSE OF THE SOCIAL REALITIES THEY ENCOUNTER AND TO FIND OUT WHAT THEORIES, CONCEPTS, AND CATEGORIES ARE SUGGESTED BY THE DATA. THE RESEARCHERS ALSO USE 'SENSITIZING CONCEPTS' RATHER THAN OPERATIONAL DEFINITIONS AND SUBJECT SELECTION OR 'THEORETICAL SAMPLING.' CURRENTLY, THE FACTORS OF NEW SCIENCE STUDY PERSPECTIVES, AMBIGUOUS QUANTITATIVE PROGRAM EVALUATION RESULTS, AND A SEARCH FOR ALTERNATIVE OR MULTIPLE-METHOD MODELS ARE CHANGING THE EVALUATION RESEARCH CLIMATE AND RESULTING IN ALTERNATIVE PROPOSALS. BLENDING THE ASSETS OF BOTH APPROACHES, (E.G.,) USING EMPIRICAL MEASURES AND PUBLIC INPUT IN THE EVALUATION OF A MENTAL HEALTH CARE PROGRAM, CAN GREATLY IMPROVE EVALUATION RESEARCH. REFERENCES ARE INCLUDED. (AOP)