Abstract: Method and apparatus for testing human performance by measuring ability to employ job-related skills in an environment requiring skill switching in the presence of a forced attention shift. A human operator is tested by use of a monitor display upon which are presented an alternating sequence of primary tasks requiring utilization of different skills. A keyboard and a joy-stick are disclosed for use in performing the tasks. A danger indicating icon is presented along with the primary task, and the operator is forced to respond to danger indications thereof by operating a switch which is provided for that purpose.