Develop information like a rototiller!
What makes a rototiller effective? What a rototiller does is go over the ground over and over in various directions, turning over the ground looking for nutrients to help the soil so you have a happier plant and planting area. The development stage during the interview should be approached in the exact same way.
When you think about the development process, you might have someone initially say, “I took 10 shirts, 5 pairs of trousers, 7 pairs of shoes…,” and so on. So what do you do? You go back and revisit areas again. You say “I’m sorry, how many shirts did you say?” and they may respond “I told you that it was 12.” How many pairs of trousers did you say? “I told you that it was 8,” and so on. What you might find is the numbers don’t match, and are greater than what we were originally told.
A funny thing about the truth - you don’t have to remember it. So how often do you go back to previous topics? As many times as needed to get the same numbers. That might not mean it’s the exact amount taken, but you’re at least moving closer to the truth - or the truth that they believe it to be. That’s what a rototiller does, and that’s what a great interviewer does. Go back over the same topics to make sure that you’ve turned over what you need to get to the truth.