What’s the 'quantified self'?

Attendees visit the FitBit booth at the 2014 International CES at the Las Vegas Convention Center. FitBit makes devices that allow you to monitor your sleep patterns, calorie intake and activity level. See more everyday tech pictures.
Justin Sullivan/Getty Images

"This above all: to thine own self be true, And it must follow, as the night the day, Thou canst not then be false to any man." -- William Shakespeare, "Hamlet"

The bard wasn't just whistling Dixie when he penned this line in his classic tragedy of betrayal, incest and greed. There are shelves upon shelves of self-help books, scores of meditation guides and an entire army of psychotherapists out there dedicated to helping people get a handle on just what's going on inside their own heads. You can't be true to yourself, without knowing who that self is.

"What a piece of work is a man!" Hamlet exclaims in the midst of one of the play's more psychoanalytic passages. More than four centuries later, advances in modern technology are providing more opportunities for humans to examine their own particular pieces of work. This is the era of the quantified self, a personal-monitoring movement that just may change the way we live.

The beauty of modern technology is the depth and range of information that it makes available with a few keystrokes, finger swipes or voice commands. Want to know what that song is playing in your local coffee shop? There's an app for that. Lost somewhere outside of Barstow, on the edge of the desert? Ask Siri for the quickest route back to civilization.

And what if there was an app for just for you? The quantified self is the idea that people can use modern technology to better track themselves, to monitor sleep, work and exercise habits, mood shifts, sexual activity, how they spend their money and what they eat and drink, among other subjects. Through this so-called "data-drive life" quantifiers can use the information to attain a wide variety of goals, from losing weight to improving the efficiency of their household chores. For some, the data is both the end and the means, a way of learning things about yourself that you might have never known otherwise [source: Wolf].