This is advice for myself.

When PhD students do their thesis defense, experts fly in to grill the student. Good thesis advisors train students to answer each question and then shut-up. Students almost always feel a temptation to elaborate.

Examiner: Why did you use that particular statistical test?

Student: We used regression because our data met its requirements for establishing cause-and-effect.

Examiners: Silence.

Student: We designed our data collection to adhere to parametric test requirements. Within the parametric set of tests, we also looked at comparison tests and correlation tests. We found a few t-test approaches that we could have used with fewer predictors…

The follow-up answer gives examiners opportunities to ask follow up questions.

So, answer the question and shut-up.

Adapted from personal communication with Dr. Randy Paterson.