Exercise 9.5 To determine if how data are gathered has any bearing on responses to a question involving substance abuse (“Have you ever used an illegal drug?”), you recruit willing participants and randomly assign them to one of three groups: Those in Group 1 will be asked the question via face-to-face interview, those in Group 2 will respond using a standard pencil-and-paper mail-in survey, and those in Group 3 will be directed to an online survey; no names or identifying information will be gathered from any of the participants.

Data set: Ch 09 - Exercise 05A.sav Codebook Variable: med