Allinall, a firm that specializes in building construction, hires Kyle, an unemployed teenager, to work in its carpentry division. Since Kyle does not have the required skills to work as a carpenter, he is provided training that helps him pick up carpentry skills on the job. Kyle learns by assisting other master carpenters and journeymen. In addition to the skills Kyle acquires, he is paid by Allinall. The form of training exemplified in this scenario is called _____.