Job Analysis: Job Classification Systems

Dictionary of Occupational Titles (
The Dictionary of Occupational Titles (DOT) was developed in response to the demand for standardized occupational information to support an expanding public employment service. The U.S. Employment Service established a Federal-State employment service system, and initiated an occupational research program, utilizing analysts located in numerous field offices throughout the country, to collect the information required. The use of this information has expanded from job matching applications to various uses for employment counseling, occupational and career guidance, and labor market information services. In order to properly match jobs and workers, the public employment service system requires that a uniform occupational language be used in all of its local job service offices. Occupational analysts collect data provided to job interviewers to systematically compare and match the specifications of employer job openings with the qualifications of applicants who are seeking jobs through its facilities. The first edition of the DOT, published in 1939, contained approximately 17,500 job definitions. Blocks of jobs were assigned 5- or 6-digit codes which placed them in one of 550 occupational groups and indicated whether the jobs were skilled, semi-skilled, or unskilled. The latest edition of the DOT published in 1977, contained over 2,100 new occupational definitions and several thousand other definitions were substantially modified or combined with related definitions. In order to document these changes, approximately 75,000 on-site job analysis studies were conducted from 1965 to the mid-1970's. These studies, supplemented by information obtained through extensive contacts with professional and trade associations, reflected the restructuring of the economy at that time.

Alternate Vendor Links:Australian Standard Classification of Occupations (
The Australian Standard Classification of Occupations (ASCO) is a skill-based classification of occupations which used as the Australian national standard for producing and analyzing labor force statistics, human resource management, and the listing of job applicants and vacancies. This system classifies jobs according to skill level (e.g., the amount of formal education, on-the-job training and previous experience necessary to perform the job) and skill specification (e.g., the knowledge required, the tools and equipment used, the materials worked on and the goods and services produced).

The Occupational Information Network, encompases changes to the DOT in terms that reflect the latest research in the field of job analysis. By identifying and describing the key components of modern occupations, O*NET supplies up-dated information critical to the effective training, education, counseling and employment of workers. O*NET contains data describing over 1,100 occupations. O*NET also contains linkages that crosswalk O*NET occupational titles to eight other classification systems (DOT, MOS, OPM, etc.). O*NET uses "Occupational Profiles" to give a short overview of the most important data descriptions on each occupation.

U.S. Standard Occupational Classification System (
The Occupational Classification System manual was created for Bureau of Labor Statistics (BLS) field economists to help ensure correct occupational matches when collecting compensation data. Available to the public, this manual allows the user to lookup job descriptions for occupations found in the NCS bulletins and is used by field economists in the classification of thousands of occupations.

MOG A Professional, Technical and Related Occupations
MOG B Executive, Administrative, and Managerial Occupations
MOG C Sales Occupations
MOG D Administrative Support Occupations, Including Clerical
MOG E Precision Production, Craft, and Repair Occupations
MOG F Machine Operators, Assemblers, and Inspectors
MOG G Transportation and Material Moving Occupations
MOG H Handlers, Equipment Cleaners, Helpers, and Laborers
MOG K Service Occupations, Except Private Household

Additional descriptions of the following can be found at: American Institutes for Research