In July, Madam expressed very clearly her experienced opinion of the documents that applicants like to bring to their NIV interviews:
If it's not a mandatory I-20, DS-2019, I-797 or the like, it is not just useless; it is a dangerous distraction. Because let's be clear: there is nothing about a piece of paper, however fancy, that will tell an officer anything about a visa applicant's intentions. Documents are crutches; flipping through them to look for a reason to issue or refuse is a futile task. A bank book, a job letter, a lease, a car title: none of it means anything. If the customer intends to stay in the US, he will willingly leave all those things behind - even if they really exist and he really owns them - without a glance. And besides, an officer's job is to interview applicants, not shuffle papers.
How do you resist the pull of papers? Don't ask for them. When offered, don't take them. If refused applicants, in their later complaints, eventually get around to the worldwide whine "...and the officer didn't even look at my documents!" the proper response is, "the officer interviewed you."