Evaluation within human service organizations is defined in terms of accepted evaluation criteria, with reasonable expectations shown and structured into a model of systematic evaluation practice. The evaluation criteria of program effort, performance, adequacy, efficiency and process mechanisms are discussed, along with measurement information requirements for each. The relationships between criteria within the program design and task environment for a service delivery operation are described. The decision-making approach to evaluation is considered with various information sources including existing records, data collection, tacit knowledge and rumors. Information is shown to be shared or unique among program treatment, research and management domains. An example of organizational diagnosis as an internal document for the management of an agency serving adolescent boys illustrates the evaluation issues discussed. The use of the Organizational Diagnosis Questionnaire, data analysis and resulting priorities for improvement are described. (CM)