In statistical analysis, there are two fundamentally opposing forces at play, which one must, at all times, keep in balance in an attempt to suitably analyse a given set of data.
Suppose we have a new drug that we'd like to test for the treatment of runny noses. We would design an experiment where some people get the drug and some people get a placebo ('sugar pill'), and then, over time, we'd see how many runny noses we observe in the two groups compared to when we started. At the end, we'd analyse all the data and determine whether the drug works.
In this determination, we can conclude that the drug either does or does not cure runny noses. And in so doing, we have two ways of being wrong; either we can conclude the drug does cure runny noses when it, in fact, does not (this is known as a 'false positive') or we can conclude that the drug does not cure runny noses when, in fact, it does (not surprisingly, this is known as a 'false negative').
Minimizing false positives and false negatives is ALWAYS a trade-off. The more you do to minimize one, the more the other becomes a problem. In the end, the trade-off determines the accuracy of your experimental test (at this point, we go beyond what is commonly accepted as 'basic statistics', into the realm of receiver-operator curves and integral calculus...a realm into which I dare not - and some might say cannot - tread).
Whether you err on the side of false positives or of false negatives really depends on your specific question. In some cases, it would be very much better to avoid false positives (e.g. Is this drug effective against breast cancer?), while in others, minimizing false negatives is preferred (e.g. Does this new food additive cause cancer?).
So what on Earth does this have to do with anything?
Well, consider this photo.
What's wrong with this (besides the blown highlights)?
Well, I don't know about you, but where I come from, people generally don't have poles sticking out of their heads.
I took this shot last November during my trip to London (...clearly). It was about 9PM, and I was returning to my hotel after dinner. It was misty and cold (...clearly), but that made for a very moody atmosphere, which I was trying to capture in the shot above.
It nearly worked. By the time I saw this guy crossing the road and focused my Leica, he was two steps too far. A potentially lovely photo of an interesting subject became a miss. A false positive, if you will; an error of commission.
Now consider this photo, which I consider a false negative; an error of omission.
The photograph above was a false negative; it would have been an awe-inspiring photo for the ages, but I never took it. Shame, really.
This highlights the key point I'd like to address: all other things being equal, should photographers err on the side of the false positive (i.e. shoot everything, and toss the crap later) or the false negative (i.e. take fewer - but hopefully better - photographs)? And what is the appropriate balance between these two types of 'error'?
First, one might be tempted to argue that in this age of digital photography, which is more-or-less free after one has purchased the gear, the photographer should take as many photographs as possible, and then edit out the bad ones later. After all, there's no additional cost to doing so, so why not?
This is essentially the 'spray and pray' method. Undoubtedly, you'll end up with some nice photographs. But you wont be learning anything in the process about how to actually make a good photograph; you'll just be a million monkeys on a million typewriters.
On the contrary, I'd like to advocate for taking fewer photographs; that is, for making more false negative errors.
Garry Winogrand was once asked whether he worried about all the pictures he was missing while he was reloading his Leica. He famously replied "There are no pictures while I'm reloading." The implication here is that the photographer is an integral part of the photo making process, and that "missed" photos were never actually photos in the first place.
As photographers approaching a scene, the first thing we should ask ourselves is not "How can I photograph this?" but rather "Should I photograph this?" I would argue that, in the vast majority of cases, the answer to the latter question is "no!"
For example, consider the following photograph.
I shouldn't have taken this photograph. It's boring, cliché, and really has no redeeming value whatsoever. And guess what? I've taken thousands of photographs just like it, and so have you. I should have kept right on walking, and aborted this awful attempt at street photography.
So how can we learn to walk away? And if we walk away, how can we ever hope to learn about what works and what doesn't? After all, we don't see the photos we never take, and thus we can't learn from them.
Well, therein lies the irony. We need to take bad photographs in order to make good photographs. We need to look at monstrosities like the shot above and recognize our faults, and try very hard not to make the same mistakes again. As we progress as photographers, we need to learn to press the shutter button less, not more. We need to learn what constitutes a good photograph, and have the confidence to say "No! This scene in front of my does not pass muster." We need to work harder to make good photographs, and a big part of this is taking fewer photographs. FAR fewer. Making more false negative errors.
Having said all of that, there is also a fundamental difference between the false positive posted immediately above and that at the top of this post. The former is, in my opinion, a photograph that could have been a winner, were it not for my relative sloth in getting the shot taken. It's a near-miss, and while I'm disappointed that it didn't work out as intended, it was worth the attempt. On the other hand, the latter photograph is pure junk, and I should have known better.
What we need to do is teach ourselves to recognize crap photos before we take them. A cursory glance at Flickr suggests we are far, far away from this ideal.
So what do you think? Is it better to take more photographs and toss the junk, or to think more up front and take fewer, better photographs?