THE FIRST TASK IN EVALUATING AN ONGOING PROGRAM IS OFTEN TO DEVISE A WAY OF DETERMINING THE PROGRAM'S OBJECTIVES AND CURRENT ACTIVITIES. IN A LARGE PROGRAM WITH MANY LEVELS OF MANAGEMENT, THIS TASK IS ESPECIALLY DIFFICULT. TO SIMPLIFY THE TASK, PROGRAM PLANNING INFORMATION PROCEDURES CAN BE AUGMENTED BY THE ADDITION OF CONCEPTS FROM THE AREA OF MULTIDIMENSIONAL SCALING WHERE SIMPLE STIMULUS OBJECTS ARE DESCRIBED IN TERMS OF THEIR COMPONENT DIMENSIONS. THE ELEMENTS USED IN PROGRAM PLANNING CAN BE THOUGHT OF AS PROGRAM DIMENSIONS CONSISTING OF CLIENTS, PROBLEMS, SERVICES, PROFESSIONALS, AND FACILITIES. TAKEN TOGETHER, THESE ELEMENTS FULLY DESCRIBE A SERVICE PROGRAM. THE DIMENSIONAL APPROACH PROVIDES A FRAMEWORK IN WHICH THE EVALUATOR CAN COLLECT INFORMATION. A TREE DIAGRAM CAN BE USED TO RELATE ANY ONE OF THE FIVE DIMENSIONS TO THE OTHER FOUR. FOR EXAMPLE, IF THE EVALUATOR'S FOCUS IS ON MANPOWER, IT WOULD BE APPROPRIATE TO FOCUS ON THE 'PROFESSIONALS' DIMENSION. THIS APPROACH HAS BEEN USED IN DIFFERING SERVICE PROGRAMS PROVIDED BY BRITISH COLUMBIA'S COMMUNITY MENTAL HEALTH CENTERS AND IN A WORKSHOP ON PLANNING CRISIS INTERVENTION SERVICES. THE CONCEPT OF PROGRAM DIMENSIONS CAN ALSO BE USED TO HELP ESTABLISH A STRUCTURE FOR SETTING PROGRAM PRIORITIES. THE MODEL COULD ALSO BE APPLIED TO CORRECTIONS PROGRAMS, DRUG AND ALCOHOL PROGRAMS, AND OTHERS. IF ALL PROGRAMS EXAMINED THEIR COMPONENTS USING THE POST HOC MODEL, AREAS OF OVERLAP, DUPLICATION, SERVICE, GAPS, AND NEED FOR SERVICE COOPERATION, WOULD BECOME APPARENT. EXAMINING A COMPLEX PROGRAM BY BREAKING IT DOWN INTO ITS COMPONENT PARTS USING MULTIDIMENSIONAL SCALING HAS PROVEN, THEREFORE, TO BE A USEFUL TOOL. THE APPROACH HAS BEEN WELL RECEIVED BY MANAGEMENT, LINE STAFF, AND THE ONE LAY GROUP TO WHOM IT HAS BEEN PRESENTED. A DIAGRAM AND TWO REFERENCES ARE INCLUDED. (CFW)