According to the text, what variable in an experiment is different for the experimental group than for the control group?

Which of the following statements about otitis media is true?

A) Plastic tubes that drain the Eustachian tubes often are used to treat chronic otitis media in children. B) Compared with children remaining at home, otitis media occurs less often in children who attend child-care centers. C) Only about 20 percent of U.S. children have experienced three or more bouts of otitis media. D) The incidence of otitis media is greatest between 3 and 5 years.

Which of the following is true about Institutional Review Boards (IRBs)?

a. Universities can decide whether to have an IRB to approve psychological research. b. The purpose of IRBs is to review research after it is conducted and review any complaints. c. IRBs review psychological studies before they are conducted to make sure they meet ethical guidelines. d. IRBs must be made up entirely of nonscientists.