Question

A researcher is interested in determining if a new intensive treatment program for high school students with alcohol abuse problems is effective. In order to recruit participants for this study, flyers are mailed to all families of high school students in the Northwest Arkansas area.  Ninety-three families decide to participate in the study. To test the main research hypothesis, the families are randomly assigned to one of three groups, with the restriction that an equal number of families are in each of the three groups (i.e., thirty-one families per group). One group of families serves as the control group and receives no intervention. A second group receives what might be considered a standard of care in that they view educational films about the negative effects of alcohol. The third group of families receives an intensive treatment program. During the study, the high school students fill out one form at the beginning of the study and one form after the four weeks of treatment indicating the amount of alcohol they consumed in the previous 7 days in terms of the number of ‘drinks’. All families have been provided a conversion chart so that the number of ‘drinks’ for beer, wine, and hard alcohol are counted appropriately. To determine if the treatment program impacts the amount of alcohol consumed, assume that the researcher is only interested in a dependent variable representing the difference in the number of drinks consumed in week 4 and in week 1 of the study (i.e., the number of drinks consumed in week 4 minus the number of drinks consumed in week 1). Note: Prior to completion of the study, fifty-nine families drop out. Using the stated setting information above, respond to the following prompts/questions:

a. Provide the Null and Alternative Hypotheses (using proper notation) Note: Provide ALL sets of Hypotheses (if more than one set exists)

b. Determine which of the following types of validity may be at risk in this study. Circle ‘At Risk’ or ‘Not At Risk’ appropriately.

-Statistical Conclusion Validity - At Risk or Not At Risk

-Internal Validity - At Risk or Not At Risk

-External Validity - At Risk or Not At Risk

Answer 1

SolutIO9 Gieven но Ho、 4