Design your interview at the trim size you feel to be most appropriate. Start your interview on the right-hand page (recto) and finish on the left-hand page (verso). You decide the number of spreads that the interview should require. Consider images, pull-quotes, page numbers, folios and other book matter. You are looking to create an engaging format for reading and comprehension.
Ideally your book model and your trimmed layouts will match. Note we have not covered grids/macrotypography in class, but your readings cover this for next week. Your readings, and your understanding of subject matter, will be your guide as to how you might place your items on the page. We will look at your layouts and work with book grids next week explicitly. You will have a week to adjust your layouts to fit the final page size.
Pay attention to line-breaks and rags. I expect the text to be typeset well. Bringhurst is a good resource for how hyphenations and spacing should work.