Exploring two methods for estimating performance tradeoff

Navon (in press) found that subjects could adjust their performance of a task to designated levels with no effect on a concurrent task, provided that the demands on the two tasks were not negatively correlated. In two experiments designed to examine the generalizability of that result under different conditions, subjects responded to task requirements less well than in Navon (in press), and performance tradeoff was not obtained even when the demands were negatively correlated.