Workers concentrating their efforts on a limited number of tasks, thereby increasing productivity is called

The correct denomination is: division of labor and specialization.

A certain process, for instance a production process within the economic activity, is divided in several stages. One different person is in charge of each stage, which in turn requires different skills. In conclusion, every person ends up being an specialist of the task performed. Therefore, division of labor leads to specialization.  

answer; pentagon papers, vietnam draft-resistor, james dean, american revolution;

answer; ///attempts to change more than once behavior at the same time;