What is the subject of the woman?

W: Hello, Professor Smith, my name is Lisa Jones. I am thinking of taking your course in social linguistics, and I am calling to find more about it.
M: Have you ever taken any course with linguistics?
W: I am a philosophy major. I have taken courses with psychology and pedagogy, but I enjoy learning languages. And the course description says that any students can sign up.
M: Yes, that’s right. But those who have ever made some research in linguistics can get a good feel for what they are learning, and will be more interested in the subject.
W: My roommate is also a philosophy major, but she didn’t take any relevant courses with linguistics. If she signed up for the course, would it be difficult for her?
M: No, there is something for everyone in this course. We will mainly discuss the relationship between language and social life.
W: One more question: do we need to bring our reference books to class?
M: Yes, you can buy them at the bookstore on campus. I’ll also provide some necessary handouts.
W: It sounds interesting. I will register today.
M: Fine. See you next Monday afternoon.