Placing children in time-out can be an effective form of punishment. Researchers
suggest this same technique can also be effective for adults. In one study, a
randomly selected group of 200 participants were randomly assigned to either the 5-
second or 10-second time-out group. The two groups were shown a series of colored
shapes and had to classify each stimulus into one or two categories. Each correct
response was rewarded with a nickel and each incorrect response was punished by a
time-out period of 5 or 10 seconds. During the time-out no stimulus was present,
and participants had no opportunity to earn more nickels. The researchers were
looking for an overall level of accuracy during 10 trials for both groups.
Question: What is the independent variable? How many levels are there? What are
they?