Recently Navon (1984) suggests that much of the dual task data that lend support to resource theories are methodologically flawed and that there are non-resource related mechanisms such as outcome conflict that could explain dual task data equally well. If Navon's concerns can be validated, the current view of workload as a resource-related concept would have to be revamped. The present research examined performance tradeoff - demonstration of resource allocation - with the optimum-maximum method. The optimum-maximum method was a variation of the secondary task technique proposed by Navon to encourage maximum joint task performance without conveying to the subjects that task performances must tradeoff. A continuous tracking task and a Sternberg memory task were used; three priority levels were used to induce resource allocation. An absence of performance tradeoff with the optimum-maximum method would support Navon's claim that performance tradeoffs may not be true indications of resource competition or task demand and therefore not reliable reflection of mental workload. Performance tradeoff was observed when the tracking task was optimized. When the Sternberg task performance was optimized, Sternberg performance was sensitive to the priority manipulations but the concurrent tracking performance was not. Peripheral vision was proposed to have protected the tracking performance when subjects were visually focusing on the Sternberg stimuli. However, the peripheral vision hypothesis could not account for the graded performance changes across priority levels. The present data suggest that the resource view is still a useful concept and the secondary task technique still could provide informative disclosure about task demand and mental workload.