Formal:
* Interviewee: This is the most common and neutral term.
* Subject: This term is used when the interview is more focused on gathering information about a particular topic.
* Respondent: This term is used in surveys and polls.
Informal:
* Interview subject: This is a slightly more informal version of "subject."
* Interviewee: This term is also often used in informal settings.
* Guest: This term is used when the interview is for a radio show, podcast, or other media outlet.
You can also use a more descriptive phrase, such as:
* The person being interviewed
* The interview subject
* The person answering the questions
Ultimately, the best word to use will depend on the specific situation.