Standard Oil of Connecticut, Inc., sells home heating, cooling, and security systems. Standard schedules installation and service appointments with its customers and then contracts with installers and technicians to do the work. The company requires an installer or technician to complete a project by a certain time but to otherwise "exercise independent judgment and control in the execution of any work." The installers and technicians are licensed and certified by the state. Standard does not train them, provide instruction manuals, supervise them at customers' homes, or inspect their work. -e installers and technicians use their own equipment and tools, and they can choose which days they work. Standard pays a set rate per project. According to criteria used by the courts, are these installers and technicians independent contractors or employees? Why?