On three separate occasions when she was out in public over the past three months, vanessa has had to rush home after being overwhelmed by dizzy spells during which her heart pounded and she felt as if she couldn't breathe. on the last occasion she went to the emergency room but a thorough examination ruled out any medical problem. nevertheless, vanessa has become increasingly fearful about having more episodes and she has restricted her activities to only the most essential outings. vanessa seems to be displaying symptoms of which anxiety disorder

Dr. robbins wants to know if there are different opinions regarding the value of public school education between native americans who have at least one relative who attended indian boarding school and native americans who have no family experience with indian boarding school. dr. robbins contacts 35 native american participants in each group. he wants each group to include younger as well as older adults, and a mix of male and female participants. he asks each person to complete a survey about their attitudes toward public education. the design of this study is: