THE FOLLOWING STEPS IN PLANNING A NEED ASSESSMENT STUDY ARE DISCUSSED: SECURING A COMMITMENT TO USE ASSESSMENT DATA FOR PLANNING PURPOSES; ESTABLISHING A STEERING COMMITTEE THAT INCLUDES COMMUNITY AND PROFESSIONAL REPRESENTATION; LOCATING INFORMATION SOURCES AND FISCAL RESOURCES; AND SELECTING THE APPROPRIATE NEED ASSESSMENT APPROACHES. THE DESIGNS, COSTS, ADVANTAGES, AND DISADVANTAGES OF THREE OF THE MORE COMPLICATED NEED ASSESSMENT APPROACHES--SERVICE UTILIZATION, SOCIAL INDICATORS, AND CITIZEN SURVEYS--ARE REVIEWED. EXAMPLES OF EACH APPROACH ARE CITED. THE VALIDITY OF THE INFORMATION DERIVED FROM EACH APPROACH DEPENDS ON THE ASSUMPTIONS UNDERLYING THE APPROACH. THE BASIC ASSUMPTION THAT THE DATA ARE RELIABLE AND VALID IS, HOWEVER, COMMON TO ALL APPROACHES. IN ADDITION, SERVICE UTILIZATION ANALYSIS ASSUMES THAT NEED CAN BE TRANSLATED DIRECTLY FROM DEMAND AND THAT UTILIZATION DATA ACCURATELY DOCUMENT LEVELS OF NEED FOR SERVICES. THE SOCIAL INDICATOR APPROACH ASSUMES THAT NEEDS BEAR A MONOTONIC RELATIONSHIP TO INDICES OF THE QUALITY OF LIFE AND SOCIAL CONDITIONS IN A COMMUNITY. THE BASIC ASSUMPTION UNDERLYING THE CITIZEN SURVEY APPROACH IS THAT INFORMATION ABOUT SOCIAL, PHYSICAL, AND PSYCHOLOGICAL IMPAIRMENTS OBTAINED FROM SURVEY RESPONDENTS OR THROUGH INTERVIEWERS' OBSERVATIONS IS COMPARABLE TO INFORMATION OBTAINED BY PROFESSIONAL SERVICE PROVIDERS. THE THREE APPROACHES DIFFER IN TERMS OF THE NATURE AND SOURCES OF DATA, PROCEDURES FOR COLLECTING AND ANALYZING DATA, AND THE AMOUNT OF RESOURCES AND EXPERTISE REQUIRED. THESE METHODOLOGICAL AND PROCEDURAL DIFFERENCES CREATE DIFFERENCES IN STRENGTHS, WEAKNESSES, AND UTILITY. FOR EXAMPLE, THE SOCIAL INDICATOR ANALYSIS CAN PROVIDE INFORMATION ONLY ABOUT THE RELATIVE DISTRIBUTION OF NEEDS IN A COMMUNITY, NOT ABOUT THE EXTENT OF THOSE NEEDS. A CITIZEN SURVEY, ALTHOUGH CAPABLE OF PROVIDING BOTH RELATIVE AND QUANTITATIVE ESTIMATES OF NEED, OFTEN DEMANDS EXCESSIVE RESOURCES, EXPERTISE, AND ORGANIZATIONAL SUPPORT FROM THE SERVICE DELIVERY SYSTEM. NEED INFORMATION BASED ON SERVICE UTILIZATION DATA USUALLY REFLECTS THE VIEWPOINTS OF PROFESSIONAL SERVICE PROVIDERS. CITIZEN SURVEY INFORMATION GENERALLY REFLECTS THE VIEWPOINTS OF CITIZENS AS FILTERED THROUGH THE PERSPECTIVES OF NEED ASSESSORS. THE SOCIAL INDICATOR APPROACH PRODUCES NEED STATEMENTS THAT REFLECT THE VIEWPOINTS OF THE ORIGINAL DATA GATHERERS--GOVERNMENT AGENCIES, DEMOGRAPHERS, AND ACADEMICIANS. CAREFULLY INTEGRATED, THE THREE APPROACHES CAN PRODUCE INFORMATION THAT ENHANCES THE INTEGRATION OF SERVICES AND THE DEPLOYMENT OF SERVICES IN CONCERT WITH COMMUNITY CONDITIONS. A LIST OF REFERENCES IS INCLUDED. (AUTHOR ABSTRACT MODIFIED--LKM)