Question

If you are a social psychologist studying how groups affect a person’s behavior, which of the following would be the most effective way of gathering information?

observe a person in the presence of others

ask a person to describe her social relations

survey people’s attitudes about social influence

talk to parents of elementary school students

Answer 1

It would probably be best to "observe a person in the presence of others."

It may come as a surprise, but much of the way that we behave, in groups, is subconscious.

What that means is that we don't always KNOW the reason for why we behave the way we do, in certain situations.
Sometimes, we may not even be AWARE of how we act, in social situations.

And that's why there would be very little value in asking someone to describe their social relations and attitudes.

Answer 2

By the way, you're welcome to post questions like this in either the Psychology section, or the Social Sciences section.

You'll probably get answers much faster, that way.