Hilda and Ethel work together to train a rat to press a lever. When they are satisfi ed that the behavior has been well learned, Hilda suggests that they remove the lever from the cage for a while and...

Hilda and Ethel work together to train a rat to press a lever. When they are satisfi ed that the behavior has been well learned, Hilda suggests that they remove the lever from the cage for a while and then reinstall it to see what happens. Ethel proposes that they leave the lever in place but disconnect the feeding mechanism. Then they begin to wonder whether they would be studying different phenomena or the same thing. What do you think?