Can someone help me with these two questions? Having trouble.?

4. Imagine a cross-sectional study was carried out to identify associations between education level and drug abuse. As they predicted, the researchers found that people with more education were less likely to be drug abusers. In this hypothetical study, give an example of how each of the following might have affected the validity of the findings (you can make up study methodology to fit your example):

Confounding (would one be family dynamics, not able to access drugs?)

Selection bias (selecting only people who went to college/middle school?)

Information bias (non-differential)

Information bias (differential)

^No idea of the other two.

5. Imagine you are designing an experimental study to evaluate the effects of a school-based drug abuse prevention program in high school freshmen. You want to see if the students who receive the program are less likely to use drugs or alcohol one year later. You have 6 school districts willing to participate in your study. Each district has 1 high school. Answer the following:

How would you decide who gets the intervention and who is in the control group?

How would you protect against selection-Hawthorne effect?

How would you protect against diffusion of treatment?

d. How would you protect against implementation effect?