<p>Wear clothes and speak in coherent sentences.</p>
<p>Don’t try to outguess your interviewer. if this is just for general admission purposes, it’s probably as much of a chance for them to sell you on Harvard as a chance to judge you. They’ll be more interested in a real person than an automoton who does nothing but study and has no interests beyond getting into graduate school (even before getting out of high school). Be ready to talk about your nonacademic activities.</p>