adoption of a uniform occupational coding system as a critical development with distinct policy implications. On balance, a uniform system is more desirable than the current collection of discrete systems strung together with cross-walks made at various times by various agencies. However, because the needs of potential users vary, some flexibility in its use should be maintained. Furthermore, we concur with the recommendation of the SOC Revision Policy Committee to form a standing body to perform such functions as continuous updating. This would relieve the need for cross-walks for rapidly changing or emerging occupations. Likewise, deficiencies in the system for particular consumers of occupational information could be routinely identified and handled, again mitigating the need to form new structures for consumer needs not properly addressed in the decennial revisions.
The Dictionary of Occupational Titles (DOT) was developed by the U.S. Employment Service to provide a catalogue of the occupational titles used in the U.S. economy as well as reliable descriptions of the type of work performed in each occupation. The latest revision of the fourth edition of the DOT was issued by the Department of Labor in 1991 (U.S. Department of Labor, 1991 ). In this revision, the key distinction was a concentration on occupations in industries that had undergone "the most significant change" since 1977. In almost every other respect, there was no change: the basic concepts (e.g., element, task, position, job, and occupation) were defined as before; each of over 12,000 occupations was still "defined" by seven items: occupational code, title, industry designation, alternate titles, body of the definition (lead statement, task element statements, "may" items), undefined related titles, and definition trailer.
The DOT occupational code has nine digits. The first three digits indicate a particular occupational group, the second three digits provide the "data, people, and things" codes for the occupation, and the final three digits differentiate an occupation from