This book presents the methods and findings of a critical review of the "Dictionary of Occupational Titles" (DOT) published by the United States Department of Labor. Following an introduction to the scope of the study in the first chapter, the book describes the study and its results in eight following chapters. Chapter 2 contains a detailed description of the current edition of the DOT to suggest to readers the nature of the document. Chapters 3 and 4 describe the ways that the DOT and associated materials are used inside and outside the Department of Labor Employment Service. Chapters 5 and 6 describe how the DOT is produced: Chapter 5 focuses on the organization of the occupational analysis program of the Employment Service, the unit charged with producing the DOT, and Chapter 6 describes the process by which the current edition was created. Chapters 7 and 8 evaluate the DOT: Chapter 7 focuses on the adequacy of the data it contains, and Chapter 8 discusses the DOT and other classification systems as tools for assessing the similarity of occupations. Chapter 9 presents the committee's conclusions and recommendations. In addition to the nine chapters of the report, eight appendixes provide data or detailed analysis of specific topics. (KC)