When answering physics questions, students often have different perspectives than do physics experts. Sometimes this difference does not mean students possess misconceptions, but might indicate that the questions need to be revised. We conducted student interviews to identify and resolve validity issues that stem from the different perspectives of students and question designers. After interviews with 35 student volunteers, we selected 14 verbal and detail-oriented individuals for repeated interviews. Instead of using interviews for soliciting and confirming students' incorrect answers, we conducted interviews as a "student consultation" process that revealed validity issues missed by physics experts. A four-stage response model was used to examine student verbal reports, and validity issues corresponding to each of the response stages were uncovered.