Saturday, 11 April 2015
Both examiners read the thesis carefully, and ask the student detailed questions. The traditional way to do this is that all three have a paper copy of the thesis, and the examiners go through the thesis page by page with their questions. Some questions are high level ("Why did you choose technique X rather than technique Y?") and some can be very detailed ("In your proof of Theorem 4.3 on page 176, I'm not sure that the third step is correct. What if the matrix A is non-singular?").
This discussion commonly takes 2-3 hours. Longer and shorter vivas are not unheard of, though if you ask me, a one-hour viva is a bit of a rip-off for the student, and a five-hour viva isn't kind, unless the length is caused by the student being exceptionally argumentative or loquacious.
At the end of the viva, the student is asked to wait outside, and the examiners decide whether the student should be awarded a PhD, and if so what corrections to the thesis are required. The most common outcome is a pass subject to minor corrections, which the student is allowed a few months to complete.
Essentially, in my experience a viva is a detailed technical discussion of the content of the thesis. Most students start out nervous, sometimes exceedingly so, but relax after a few questions as they realize that this is just a technical discussion of the sort that they have had many times before. That said, even if your research career is long, it is rare that a trusted colleague will provide you with several hours of detailed feedback on your work. To be part of a discussion like this, on either side of the table, is a privilege: most work is ignored, so any criticism is a compliment.
I am sure that the process is more tense if the examiners believe that the quality of the thesis is borderline --- fortunately, I haven't yet been asked to examine a thesis like that. If portions of your thesis have already been published in prestigious venues, and whether this is possible at all varies greatly across disciplines, then you can be fairly sure that your thesis is not near the borderline.
A colleague suggested to me once that a viva is like a negotiation. If your thesis represents a sufficient amount of research of acceptable quality (and if it was indeed you that wrote it), then you will pass. The negotiation is over which corrections will be required. Responsible examiners do not want to require additional experiments that will require months of work, if the thesis as submitted is of excellent quality. But they also don't want a thesis to be passed with gaping holes in its argumentation. The purpose of the discussion is to sort out which potential concerns are which, and your voice in this discussion matters --- you wrote the thesis, so you are the expert in the room.
Sometimes an examiner asks a question with an eye to a correction being required. Maybe you think, "yeah, that's a good point, I should add a paragraph on that" --- in this case, don't hesitate to say so. On the other hand, if providing a good answer to the examiner's question would require months of additional research, politely explain why, while also giving the best answer you can given what you do know. What you don't want to do is argue every point strongly, even when the examiners are clearly right... that is not good negotiation strategy.
A bit more about who attends the viva. The internal examiner is not the supervisor, in fact, they will not have been involved with the thesis research at all. It is not unusual for the internal examiner to be a bit of generalist with respect to the thesis topic, although when I have served as internal, I have usually been able to make out the thesis reasonably well. Presumably this is because the School of Informatics is large enough that there are many theses in machine learning and natural language processing that need to be examined.
The external examiner is chosen specifically for their expertise in the subject matter, and to serve as an external is generally seen as a minor indicator of prestige. A certain amount of deference is paid to the external in the culture of the process. Even so, I have the sense that part of the role of the internal is to be accountable to the University (for following correct procedures) and to the student and the supervisor (to make sure that the examination is fair to the student). I have read and heard horror stories of aggressive external examiners but never witnessed one; to the contrary, the examiners who I have witnessed have all gone out of their way to be kind to the student.
The role of the supervisor in the viva, I think that this may vary slightly across institutions. At Edinburgh, the supervisor is allowed to attend the viva, if the student permits, but not to participate in any way. In my experience as internal examiner, the supervisor has attended about half the time. One supervisor silently took notes to share with the student, which I think is quite a kind thing to do.
Finally, although the description is written for a US audience, British academia also fetaures the snake fight portion of your viva.
(Written in honour of my first PhD student graduating. Congratulations Yichuan!)
Saturday, 3 January 2015
Due to a recent bout of jet lag,1 I have found myself this week waking up at 5am.
So I am experimenting with reading a paper first thing in the morning.
I am hoping that starting off the day with an intellectual task will help me to avoid
"administrator brain", which FSP describes in an excellent post.
So far (well, two days in) it has been really fun. It helps me to stay motivated, because after writing 50 emails in a day, your mind gets lost in minutiae, and you forget that you came to this job to learn, to help people, and to be creative.
Can't promise that I'll keep waking up at 5am, though.
I have begin scheduling posts well in advance, so this bout will no longer be recent when you read this. ↩
Saturday, 6 December 2014
A large part of taste in research is deciding what not to work on. You might choose not to apply method X, even though you don't really understand it, because it has a reputation for being fiddly and difficult to get right. You might choose not to work on topic Y because you think that even though there's a lot of people writing papers about it, its goals are too ambitious to ever be met. This extends all the way to entire fields of research. I could name a few popular fields within computer science — with active research communities, large amounts of external research funding, leading researchers with fancy prestigious awards — that I suspect are being investigated in entirely the wrong way, and that I personally think are currently pointless.
I could name them. Will I? No.
Why not? To protect my career? If I am honest, probably in part yes. But what I tell myself is different. The real answer, I think, is that my opinion of these areas is poorly informed. Because I think these areas are uninteresting, I haven't studied them carefully, and so I don't know how they've attempted to address my naive objections. It would be arrogant and professionally irresponsible to publicly denigrate the hard work of many people without having even bothered to read it.
This leads to a paradox. It's impossible by definition for me to become better informed about these areas, unless I decide to actually start researching them. In order to be fully confident that an area is uninteresting, you need to study it — and that study itself is part of doing research! But you can't do careful reading on every research area that seems bogus at first impression, because then you would do nothing else. Instead, you have to take intellectual shortcuts, and do the best you can with limited time to think. Those research areas that smell a bit off, you ignore them until either they die out, or a major success forces you to reevaluate. Part of taste in research is deciding what to study, and what to ignore.
This is the paradox of taste in research. Your decision of what not to work on is, by definition, always ill-informed.
Wednesday, 5 November 2014
I walked home past several people setting off sparklers and fireworks in the meadows. In Edinburgh celebrations of Guy Fawkes night are not elaborate, but you can smell the gunpowder.
A good thing, because otherwise I can never remember what night it is. The traditional rhyme
Remember, remember, the fifth of November
is about the worst possible mnemonic that I could think of. It fits the meter just as well to say
Remember, remember, the FOURTH of November
but you aren't meant to remember that one. Personally I prefer
Remember, remember, the ninth of November,
because that happens also to be my birthday.
Much more sensible to base the rhyme on the part that's easiest to confuse.
Instead, how about:
Let the memory survive
That the king was still alive
On November five.
Now you won't forget.
Saturday, 1 November 2014
Just before I went to my first conference, I thought, "Hey, I guess I should be professional now!" and printed out business cards on the best card stock that I could find at Staples. Apparently, of the hundreds of people who attended NIPS that year, I was the only one who had done this. I handed out one card, received none, and assumed that everyone must just Google each other after the conference.
From an objective standpoint, from the perspective of maximizing the efficiency of scholarly communication, this is of course ridiculous. The only explanation that I can imagine is reverse snobbery, the same reason we would never wear a suit and tie to work. But at the time, I didn't worry about this. I just did what everyone else did.
I'm eleven years older now, and my memory is much worse. At the last conference I attended, I thought, "Hey, wouldn't it be great if next time, I could go home with a list of every new person that I met, perhaps on a durable but unobtrusive slip of paper?" I do worry about people giving me funny looks, but I can't very well pretend to myself that I am creative and iconoclastic if I always do what my friends do.
So if I meet you at NIPS this year, do not be surprised if you receive an unobtrusive slip of paper from me. I hope that you enjoy the word cloud on the back.
Saturday, 16 August 2014
I’d like to talk frankly about a real threat to the British monarchy.
First, monarchs like to emphasize continuity and tradition by reusing names from previous monarchs. This is understandable as, in a constitutional monarchy, continuity and tradition are the monarchy's main assets. Perhaps for this reason, a British king hasn’t taken on a previously unused name since George I in 1714.
However, this bumps up against a contradictory historical tendency, namely that British monarchs have had what might be described as a rich and varied history. British kings aren’t eager to remind people of their more colourful predecessors. Many names are therefore out of bounds.
The result is that the British monarchy is rapidly running out of names in the male line. For example:
Henry — It is difficult to imagine the king who would want to be Henry IX, and even more difficult to imagine the woman who would want to marry him.
Richard — Who wants to be the successor of the King in the Car Park? And there was the business with the Princes in the Tower.
Edward — Although the abdication of Edward VIII might be viewed more romantically by modern eyes, the Nazi sympathies, not so much.
John — The Magna Carta was written to protect people from him.
James is right out.
Once you factor in this history, there are very few names left. Charles is still OK. Charles II granted the charter of the Royal Society; perhaps a future Charles III could also take an interest in science. William and George are unimpeachable. Albert is a possibility, although the famous Albert was only a consort, making the name a bit of a risk: the last prospective King Albert decided at the crucial moment to become a George instead.
This is shaping into a crisis. One can imagine a time, in the coming centuries, when the only choices left to British kings are Charles, George, and Cnut.
Sunday, 20 July 2014
I spend a lot of time in coffee shops. I'm writing in Amsterdam, so let me clarify that I do mean coffee. I like coffee shops because: a) I like coffee, b) I find them relaxing, and c) and it is a way to be around people without the awkwardness of being obligated to talk to them.
It's very important to choose coffee shops wisely. Before I go on vacation, I always do careful research about where the best coffee shops are (again: for coffee). But "best" is complicated. You need to think about what aspects of the coffee shop experience are most important for your trip:
A) Quality of the coffee. The presence of single estate beans or fancy hipster brewing methods is a good sign, but it doesn't matter what equipment they have if they don't know how to use it.
B) Ambiance. How easy is it to relax? Or to concentrate? There's one place I used to go to often — closed now — awful coffee, but near me, and really cool decor.
C) Quality of food. Pastries only? Sandwiches? Hot food? How good?
D) Location, location, location.
E) Work friendly or people friendly? Some cafés you go to with a laptop, some you go with a group of friends. A book is usually always OK. Interestingly a tablet feels more to me like a book in terms of social acceptability than a laptop but maybe I'm biased.
I know one cafe where 24/7 there was always a row of six people staring at laptop screens. Nothing wrong with that, as long as you're bringing a laptop too.
F) Attractiveness of clientele. I never go to cafés specifically to pick people up, but it's always nice to be around people who seem interesting.
G) Staff. This is complicated because while nice banter will always make me smile, I am also happy to be left alone.
Happy to hear if there are important criteria that I am leaving out.