In a Memory Experiment,the Subjects Are Asked to Learn Three

Multiple Choice

In a memory experiment,the subjects are asked to learn three lists of words.Each of the word lists is of equivalent difficulty.The first list contains university names,the second list is of dog breeds,and the third list contains kitchen appliances.After running 20 participants,the researchers notice that recall of university names,the first list that the participants learn,is much higher than recall for either of the other two lists.How can the researchers make sure that one list is actually easier to recall and not just an artifact of the way the test is set up?

A) Confound one of the variables.
B) Take a random sample of the participants' answers.
C) Change all of the university names to non-American proper names.
D) Counterbalance the word lists.