In the 1960s, when Dr. John Holland was ACT Vice President for Research, he developed a hexagon arrangement of six occupational types. Dr. Dale Prediger began the work to extend the applications of Holland's hexagon in the early 1970s, and the first World-of-Work Map was introduced by ACT, Inc., in 1973.
The Map is based in substantial research involving analysis of several key databases: expert ratings of basic work tasks from the Department of Labor's Occupational Information Network and ratings from the Department's Dictionary of Occupational Titles. Interest inventory scores of more than 200,000 persons in 640 occupations provide a third source of data.
The Map has been revised several times in response to the changing nature of many jobs. The most recent revision was introduced in 2001.