Here's why:
* Underlining: Underlining is typically used for titles of books, movies, plays, etc. Interviews are not considered titles.
* Quotes: Quotes are used for direct speech or to indicate a specific piece of text that is being quoted from another source. While an interview will contain quotes from the interviewee, the entire interview itself isn't a quote.
Instead of underlining or using quotes, you can use:
* Italics: To emphasize the word "interview" in a sentence.
* Bold: To make the word "interview" stand out in a document.
* Normal text: You can simply use normal text when referring to an interview.
Examples:
* I conducted an interview with the author.
* The *interview* revealed some interesting insights.
* I read the transcript of the interview.