INTERVAL PRODUCTION AS A SECONDARY TASK WORKLOAD MEASURE: CONSIDERATION OF PRIMARY TASK DEMANDS FOR INTERVAL SELECTION

Twenty-eight participants performed a surgical training primary task along with a concurrent time estimation (interval production) secondary task. Fourteen participants were given a primary task that varied in motor demand; the other fourteen performed a primary task that varied in cognitive demand. Time estimation is an attractive option as a workload measure due to its low cost and ease of implementation. Currently it is unclear whether the structure of task demands influences the sensitivity of time estimation tasks that use different intervals. The sensitivity of both a short (3 second) and long (21 second) interval were observed in tasks that differed in level of workload. Results indicated that short intervals were more sensitive to changes in motor workload while long intervals displayed more sensitivity to changes in cognitive demand. With the rapid evolution of new support technologies that enhance performance in complex tasks comes a demand for performance-based workload measures that are both relatively inexpensive and easy to administer in a wide variety of contexts. One such context where these measure