forms of artistic work that have a project structure. There is evidence that project organization is spreading to other organizational contexts, in part, because of the spread of professional and technical work. The parallels between craft, professional, and technical forms of organizing highlight a crucial and often overlooked implication of the spread of professional and technical work: the increasing prominence of horizontal divisions of labor.
A horizontal division of labor implies a dispersion of authority among experts from distinct occupational groups. The logic behind this way of dividing work and authority is that knowledge and skills are domain specific and too complex to be fragmented and nested; thus individuals, rather than positions or jobs, become vessels of expertise. Knowledge is preserved and transmitted through extended training rather than through the rules and procedures that characterize bureaucracies. Occupational groups retain authority over their own work, while interacting with members of other groups to manage their respective components of a task. In a horizontal division of labor, knowledge and skills tend to be transportable across work sites. Prior to the industrial revolution, except for the military and the church, horizontal divisions of labor were the primary forms of organizing. It was only with the development of the factory system that vertical divisions of labor become more prominent.
A resurgence in the horizontal division of labor should pose problems for organizations and individuals quite distinct from those they have faced in the recent past. One such problem concerns the nature of careers. Research has long demonstrated that relatively few scientists, doctors, or lawyers desire careers structured around hierarchical advancement. The same is true for most engineers. Although the literature frequently suggests that engineers desire managerial careers and although there can be no doubt that engineers move into management at greater rates than do members of other professions (Perrucci, 1971; Ritti, 1971; Zussman, 1985; Whalley, 1991), surveys of engineers nevertheless routinely indicate that two-thirds of all engineers are more interested in careers that involve increasing technical challenge (Bailyn and Lynch, 1983; Allen and Katz, 1986). In a series of studies of technicians, Zabusky and Barley (1996) report that most techni-