Did the WL-interview this morning. I think it's safe to assume that the invite for an interview goes out to everyone who previously declined to be interviewed (as I did). If you interviewed before, there's perhaps a chance that they don't solicit additional information from you since (or if) they feel they already have a good impression of you as a person.
As to the interview itself, I understand that the confusingly mentioned 'status page' is actually the KIRA interview page itself (which will be linked to in your invite email). The page records all your previous inputs once you're registered, including computer set-up or already completed questions. You can't re-do questions but you can elect to do some questions now, and the other ones at a later date. That page has nothing in common with your applicant Status page at NU, so I understand why some people (including myself) got confused by the email's wording.
I would definitely recommend using the practice questions to get a good questions on timing yourself, testing the audio quality, and so on. I realized I was rambling, and quickly changed pace and concision afterwards. You get to watch your own answers, so this is helpful. What's brutal about the actual interview is that you don't get to re-do a question if you mess up. There's two ways you can mess up - you can break off a question prematurely, or with the written questions, you can keep on typing before hitting 'Submit'. I nearly panicked because I did the latter, and nearly failed to submit a fairly long essay for my fifth question. So watch the time bar carefully.
In terms of content, again - check out the practice questions. There's one question that will always come up, as it has to, and that is "Why Northwestern". So you can expect that to come up in the actual interview. The rest, there's no overlap. But there's also another difference they don't mention: while practice questions has you answer for 1 minute, the actual questions allocate you 3 minutes. That's nowhere announced.
I'm not going to reveal the questions I had to answer, but suffice it to say they clearly allow you to elaborate on things you'd have said in your personal statement regarding your past accomplishments, current fields of expertise, and future career interests. This is not heavily signaled, but I would recommend bringing each question, no matter how flippantly worded (from the practice samples: 'What's your favorite pet?', 'What's your favorite app?', 'What's your favorite candy?'), back to you as a person in a more general sense. That is, answer the question seriously and fully, but dedicate the second half (minute 1:30 to 3:00) to addressing a larger element of your personality or theme in your personal/professional life, then tie it back to your application. I can't say if that will specifically work for Northwestern, or whether it'll meet success, but as a person with prior interviewing experience (on both sides) I can tell you it's a great deal more exciting than to listen for 3 minutes about a person's love affair with Snickers bars.
Finally, I'd say - try to enjoy this. You get to set up the interview in a space you're comfortable in, so there's a significant amount of control on your end that traditional interviews don't give you, and which will impact how relaxed you are and how much you actually enjoy it - which in turn will absolutely help to make a solid impression. As an interviewer, I find few things more grating than the forced smile perfected by Kudrow in her role as Valerie Cherlish
- "You see that smile? It means I'm dead inside."