There seems to be a bit of confusion about the distinction between the terms "identity" and "identification" in popular discussion. The terms are often used interchangeably, and are used differently in different contexts. I thought I would write a bit about these and other related concepts, including a new concept that we introduce.
The terms are infused with the complexity of multiple disciplines (philosophy, psychology, sociology, neurology, religion, etc.), each with their own usage and take on the meanings. To add to the complexity, identity is now an important concept with different meanings for government, commerce, and the internet.
Who are you? Are you different from your neighbor? From your identical twin? Is there something about you that distinguishes you from everybody else? The subjective versions of this are the "self-image" (a person's own model of his identity) and the identity perception of someone by others. Is it "the self" or the the ego of psychology? Is this the "soul" of certain faiths? Is it the mind? The brain? What about the body? Is identity a product of nature, nurture, or both together? Many questions.
Most of us cannot be relied upon to accurately describe our identities, though sometimes best friends can get pretty close (we get closer, see below). This is the reason metadata contributed by users about themselves or their works is not considered accurate. A personal tag cloud is just an ego trip. It is highly subjective. Web page meta keywords are no longer relied upon by search engines or advertisers because they are so inaccurate. This is the source of the delay in the promised "Semantic Web" revolution.
I like to think of Identity as that mental thingy that distinguishes you from every other person. It is the objective, non-corporeal entity that is the sum of all the biology and environmental influences that constitutes what it is to be you, at this moment in your life. Despite the similarities, you have a different identity from your identical twin because your minds and bodies have had different experiences. You also have a different identity than yourself of one year ago because you've had new experiences... and of course your brain has suffered some oxidative degeneration ("vegetable oil", anybody?).
But in the real world, and for the purposes of government, commerce, most things that make the world work, it is the corpus that counts. You are you because you are contained within the body of you. Identity equals body. The body that is recognized as you by facial recognition, and authenticated by fingerprinting, retinal or corneal scanning, etc. Science fiction has enjoyed this mind-body identity confusion with numerous examples in movies and television ("This body is not mine, and I have to be clever to convince my friends of my true identity").
Now, identification is the assertion that you are actually you ("I may look like a fly, but it's really me!"). Having the face of Nancy is an assertion that you are Nancy, i.e. your friends and family will identify you as being the identity they call "Nancy". Identical twins and masks can confuse the identification in opposite ways.
One can authenticate their identification with some available mechanism that provides some level of authentication. Visual similarity to your picture ID card (is ID "identity" or "identification"?) is a common form, voice recognition on the phone is another common one; "Hello, it's Nancy" works only if you sound like Nancy. We can authenticate the body fairly well, but the mind is more difficult ("Nancy doesn't seem like herself today. Maybe she's been taken over by an alien.").
On the internet, there are various uses for the terms identity, identification, authentication and anonymity. Your Facebook profile is a reflection of your identity, or an exhibition of your identity, most probably with identifying elements like your name and photos. In some cases you may have multiple online "identities" representing different facets of your actual identity. Those facets are sometimes identified by usernames and avatars indicative of the identity or sub-identity or idealized identity they represent.
For a new user, identity may initially not be important: an anonymous user is self contained, requiring no identification or authentication. But as other users get to know that user, they will expect that it is consistently backed by the same identity. As it develops a reputation, the identity behind that user identification will want to maintain exclusive ownership of that identification, via some kind of authentication that ensures such exclusivity.
There are many systems for authentication, each attempting to ensure that the user instance is an active reflection of the same identity. Online banking is an example. There are two levels of authentication here. First, the owner of the username is the identity called "Nancy" with these identifying personal details. Second, that the username instance (i.e. the just logged in identity) is also the "Nancy" identity (access management). The first is corpus related: Nancy walks into her bank and gets her login details based on corpus identity. The second is mind identity: does Nancy remember her username and password, or where she scribbled them?
Our project introduces another concept to the scene: the identity proxy. In our case, it is an objective proxy of your identity that makes choices on your behalf, likely the same choices you would make, even when you are not logged in. In a sense, it is like an email filter that follows your instructions and helps you deal with information overload by automating that small bit of your identity that prefers certain emails over others. Ours is much more powerful in reducing information overload because your identity proxy automates the filtration of all available information and options, in every domain of life. Your identity proxy is an accurate and objective reflection of your identity and it understands and automates your decision making processes. There is no greater weapon against the tyranny of choice and information overload.
Without an email filter, it would take us hours per day to delete the spam and read the relevant emails. We would quickly lose patience and only find a fraction of real emails. Likewise, it would take us thousands of years to meet every other human, listen to every song, read every book, evaluate every vocation, etc, in order to find the ones we like. It's a big world, and, sadly, life is short. The identity proxy does not live our lives for us - it makes our lives richer by allowing us to find those things that we wouldn't have found unless we lived for thousands of years.
Also, at it's core, the identity proxy requires no corpus identification, i.e. no personal or demographic details are necessary in the registration process. Nobody can use the registration information to track you down (track down the corpus). Privacy is intact.
Your identity proxy is singular. Having more than one identity proxy is a waste of time because every time you register accurately the system should see you as being identical (or close) to your previous proxy. Registering inaccurately serves no purpose because the proxy will make choices that do not reflect your identity, and the choices will not be as fulfilling for you.