What I am looking at is actually "Why" but not "What"

Weeks ago when we were talking about "Focus Group" research method, I was struggling and debating with myself -- when I was doing my undergrad Management courses, one of my professors were strongly opposed to the idea of "Focus Group" in general and university students as sampling in particular. I bought in his idea that "focus group" with inappropariated sampling will lead to "group think", which will result in strongly bias. Therefore, within the past two weeks I kept struggling with myself on the sampling scope issues. Finally I have seen the light from Lucker's Field (and Other) Methods chapter. As Luker (2008) mentioned, "Regardless of whether things happened the way people said they did, what interests us is that people chose to tell us that they happend that way. Interviews are, almost by definition, accurate accounts of the kinds of mental maps that people carry around inside their heads, ad that it is this, rather than some videotape of "reality", which is of interest to us" (167). So what I should be looking at is not about what the interviewees have said, but rather why they would choose to say so. In this way, even there is a group think, by looking at the process for them to come up with the similar answers I can actually identify the social pattern thus locate the issues or conflicts.
Besides, Luker interview question design is also insightful to me. In my preliminary research project, I have designed to interview several senior managerial staff of my research subject organization. Now that I have read Luker's interview questions, I will have to redesign my own questions so as to make them lead my interviewees to the issues of the organization that they might not aware of or would not be willing to address unless I ask.