Designed to help occupational analysts, employment and training operators, guidance counselors, and vocational educators to better assess the source, content, and level of training necessary to achieve the desired skill requirements for most occupations, this report contains an analysis of training patters for clusters of occupations, a case study, and appendixes of technical information. Part 1 reviews concepts, trends, and data related to training in six chapters: (1) Introduction, (2) Definitions, (3 and 4) Patterns of Training: Pre-employment and Post-employment, (5) Data Sources on the Supply and Demand for Labor, and (6) Using the Data. Part 2 (chapter 7) is an attempt to apply the principles of part 1 in a case study of New York City. Part 3 is a series of appendixes giving technical information on the level and types of training for detailed census occupations, including these: 1970 Census Occupational Categories by Training Clusters and specific information on these clusters of occupations: health care; apparel manufacturing; metal working and machine trade; computer or electronic data processing; construction; printing crafts; clerical; sales; appliance repair; consumer goods; and insurance industry. (YLB)