I am asking from the perspective of interviewer but am also interested in views from interviewee perspective if they can help. Are there certain positions where an in-person interview is preferred assuming parameters like distance etc. are a non issue for the recruiter. I also wish to explore situations in which walk-in style interviews are preferred over scheduled interviews and vice-verse.
Both sides miss out on a lot of the body language, so it far easier to misinterpret.
As an interviewer, you miss out on the chance to check with others about their perception of the interviewee. In an in person interview how an interviewee treats people he casually run into is often taken into account. They are looking for fit and people who are rude to the receptionist are often eliminated for that alone. You miss out on evaluating the person's hygiene. Yes that sounds silly but I once had someone show up for an interview for a client-facing position wearing no shoes and very visible dirt up to her knees (well that was as far as I could see). So it really is a factor. She would have appeared fine in a video interview where we only saw her face.
It is also easier for a remote interviewee to have someone else in the room feeding them the answers to technical questions. So many interviewers are likely to be primed to be more impressed with the answers they get from people in person. And people do relate better to people they have actually met. There probably is even an unconcious bias in favor of the people they met in person in many cases. I bring that up because the interviewee would have to work harder to impress on a video interview because there is a bias to overcome in many cases.
From the interviewee side, you miss a chance to independently evaluate the work conditions, how the people in the office appear to relate to each other (If you have have ever walked into an office where everyone hates everyone, it is appranet within seconds from the tension in the body language and the tone of voice people use to each other). You miss out on seeing if the noise level is such that you can live with it, you miss out on meeting people who are not the interviewers (and sometimes you run into someone who knows you who will give you a good reference). Does the place seem regimented or relaxed?
Interviewers will often make a place sound better than it actually is (and to be fair, they aren't necessarily deliberately lying-one man's quiet, relaxed place can be another man's noisy, tense place), you can better evaluate the place with a chance to walk through the offices yourself and observe for yourself.
Does this mean you should never video interview? No, sometimes it is the best option if the person is in another country and you don't want to spend the money to bring them in. Just that both sides of the table may have to work harder at it to get the information they need to move forward in the hiring process. As na interviewer, I likely would not want to consider it for a client-facing postion (sales, account management, consultants, etc.) where you really really need to knwo how the person relates to other people in general. As an interviewee, I would not want to do it all if there are any other options avaiable because you are at a disadvantage in comparison with people they interviewed in person and you don't get a chance to evaluate them as well as you might want.
I've attended interviews that mix both at the same time: One of the interviewers was in person with me, and the other over video from another city. As an interviewee, I didn't feel much difference. This was for a software developer position, with no programming during the interview. I think that is why it was done with a mix, since showing programming for both persons at the same time might be challenging - it's hard to see whiteboard/paper through video, and the other way you would need to setup a computer for this purpose.
So in this situation, I think you can get away with video conferencing. But if you need any writing, pseudocode, or drawing charts, I think this is the case when video conferencing falls short. It would probably be quite difficult to do a good interview over video.
My interviewing (hiring mgr) experience is that an online interview can weed out candidates quickly. Online interviews weed out people that are simply not cut out for the job. They usually last under 30 minutes, and can be done from home by a single individual.
Several candidates will crash and burn when asked very simple questions about what is on their resume. If a "Senior" dev prospect cannot answer a simple SQL question, there is no need to waste time doing an in person interview.
I would never hire someone based on an online interview only
You need in-person interviews to ensure the guy didn't cheat his way through your online interviews. You will also be able to have a much more in-depth conversation, and include some white-board problems that would be too complicated over phone\skype.
It'll also be easier to gauge enthusiasm as in person interviews usually last several hours, and involve multiple people. It also gives you the chance to make sure the candidate has good hygiene, can dress appropriately and show up on time.
Video interviews are just one step in the hiring process. More and more companies are using video interviews these days because it enables them to connect with candidates earlier on to gain greater insight. Most of our customers actually use them as a replacement for the phone screen. Thus, they are not totally abandoning in-person interviews, but using video interviews as a more efficient screening tool which allows them to quickly get to the step of inviting the best fitting job candidates into their office. Also, the majority of companies that we see using video interviews don't use them as a replacement to the in-person interview unless an in-person interview isn't feasible because of location, scheduling, etc.
Additionally, employers can cut down on valuable money and time being wasted by using video interviews. They also share with candidates the relief of less hectic scheduling. For example, with a One-Way interview, candidates have the convenience of being able to record their answers using a webcam or mobile device whenever, wherever. This interview also gives candidates the ability to think through questions and prepare a great answer before recording. Each question is presented the same way and in the same order to each candidate; therefore, one candidate doesn’t have an advantage over another candidate in any way.
A job candidate will be seen at some point in the hiring process. There’s no reason that the first time can’t be via a video interview. If the employer chooses to eventually have the candidate come in for an in-person meeting, they already have a sense of their personality and characteristics from their video interview to make better hiring decisions.