In a true experiment, the researcher _______ variables, and in a quasi-experiment the researcher _______ variables

Studies on long-term memory in elderly people usually show that

a. elderly people show substantial deficits in implicit memory. b. elderly people and young adults perform similarly on all the major tests of long-term memory. c. elderly people are usually somewhat better than young adults in recalling people's names. d. in manyâ€"but not allâ€"areas, young adults and elderly adults perform similarly.

Which approach has been most effective in reducing criminal activity in adolescents?

a. "Scared Straight" approaches when former criminals speak to at-risk adolescents about prison b. community service approaches when adolescents are required to help their communities c. multisystemic approaches that include job training and neighborhood activities d. foster system approaches when at-risk youth are placed in foster homes with authoritative parents