A researcher has studied subjects’ ability to learn to translate
words into Morse code. He has experimented with two treatment
conditions: in one condition, the subjects are given massed
practice; they spend 6 full hours on the task. In the other
condition, subjects are given distributed practice; they also spend
6 hours, but their practice is spread over four days, practicing 2
hours at a time. After the practice, all subjects are given a test
message to encode; the dependent...