S: I've been asked to write as if I'm an expert. Is that what you call public engagement?
L: Yes, public engagement is when you write for people who are not experts, and who haven't studied in the same field as you. So you are explaining to them some key ideas in your field.
S: Do I talk about my research or make an argument?
L: Not normally, no. The important thing is not what your argument is but what is generally known in the field, which is relevant to the needs of the person who is going to read what you've written.
S: Oh, so I'm writing as if for a wider audience.
L: Yes. Of course, what really happens is that your lecturer or tutor reads it but you pretend that you are writing for somebody outside the university.