Ergometrics, the application of psychometric principles and procedures to the study of human work, draws from theories and principles of human behavior as well as from established procedures in psychological measurement and job analysis. The project described employs ergometrics to describe, compare, and group occupations for educational purposes. An Occupation Analysis Inventory (OAI) was generated containing 622 work elements (descriptions of activities and conditions). Ratings on the work elements were obtained by relevance to 103 defined human attributes (resulting in attribute-requirement weights). The OAI work elements were then correlated and subjected to factor analysis. Five test batteries and inventories measuring various abilities, interests, needs and satisfaction were used to discover relationships between these variables and measurable behavioral potentials. Clusters of occupations were found to be discriminable and significant cross-validated multiple correlations between OAI factor scores and aptitude test scores were obtained. Other findings also indicate that a meaningful and potentially useful set of occupational descriptors has been developed and validated. (MS)