The specific objective of the research described in this report was to develop guidelines for decisionmaking by the Office of Manpower Utilization (OMU), Marine Corps Headquarters, in the selection of occupational field (OF) sample sizes to which task inventories will be administered. The report is designed to provide action-oriented answers to major questions about both size of samples to be drawn and the strategy for planning and conducting the data collection process. Generally accepted essential requirements for the design of optimum samples are discussed and major implications of these requirements are spelled out as they apply to samples in Task Analysis (TA). A summary of requirements for a sampling design for OMU is given along with research findings that suggest a uniform optimum size for OMU samples. A recommended sampling strategy is also outlined for guidance in data collection. The appendixes, covering half the document, present in tabular form data from stability tests conducted in the analysis of responses to different occupational field task analysis inventories. (Author/HD)