Who am I? Is this real? What does it all mean?

These aren’t just questions that a philosophy professor might use to challenge a class of college students. They’re also practical considerations everyone faces in the online world. Should you use your real identity in your online discussion groups, blogs, or instant messages? Or should you manufacture a false ID?

In one Web discussion site I frequent, one of the posters made the comment, “We use handles online.” Yes, many people use these chosen nicknames. But not everybody does.

On one recent, random day I analyzed the names used by the 108 people who had logged onto a randomly chosen Web discussion site. Most people used a handle that didn’t appear to have any meaning or was some hidden combination of their first and last names with perhaps some extra letters or numbers. The next largest group chose a meaningful handle such as captaincoffee, Dads Stuff, Eagleeye, homevideo, labmom, lostDutchman, Oldman, superbeast1098, TreasureGirl, and WildJon. Then came those who used what appeared to be their real first names. The smallest group, just three of the 108 people, all of whom were experts or well-known in their field, used their full names.

There are benefits and drawbacks to each approach. Depending on the group, it may be difficult to be taken seriously if you use a handle such as funkypunk. On the other hand, choosing a handle that broadcasts something about your interests, aspirations, or fantasies is a shortcut way for others to peg you.

Sometimes using a handle or assumed name is self-protection by preserving your privacy. One example is participating in a discussion group about a sensitive matter such as spousal abuse or an infectious disease. Another example is wanting to speak freely about politics, religion, or similar topics without worrying about possible repercussions at work.

But cloaking your identity can take on a sinister hue if you create more than one ID to verbally attack others; it can appear psychopathological if you use the false identities to talk with or defend yourself. Such deceptive online identities are derogatively known as “sockpuppets.”

Kids have fun making up identities online, indicating that their hometowns are on the planet Jupiter and using pictures of their dogs to illustrate their likenesses. Parents want their kids to protect their identities online to decrease the possibility of predators, who may try to gain the trust of a vulnerable, gullible child with the intent of meeting that child in person.

The online dating scene brings its own twist to online identity issues. As pop psychologist Joyce Brothers once told me in a telephone interview, “There is no truth-testing online. No one verifies that you are who you say you are.” As Peter Steiner wrote in his famous July 5, 1993, New Yorker cartoon, which portrayed a dog typing at a computer, “On the Internet, nobody knows you’re a dog.”

Those who pretend they’re more than they are, in words or in pictures, typically get their just deserts when an online relationship graduates into the real world.

Digital technology makes it easier than ever to fictionalize pictures. Since the introduction of Photoshop in 1990, it and other image-editing programs have let people correct, enhance, or completely change photos with their computers. Perfect white teeth, sparkling eyes, and a face free of wrinkles, freckles, pores, moles, pimples, or other blemishes are just a few mouse clicks away.

The latest digital cameras come with built-in features that can do some of this work automatically. Some Hewlett-Packard cameras include a feature that makes you look thinner without dieting, while some Olympus cameras can give you a Caribbean tan without stepping aboard an airplane.

Pictures that lie have more serious implications than online dating fudging. The Image Science Group at Dartmouth College recently released tools that help the law enforcement community detect photo fraud, and work is underway to do the same with video fraud.

The ultimate in new reality is virtual reality, an old concept that for years has promised a totally immersive experience incorporating all of the senses. Wearing “data outfits,” we’ll not only see and hear the sights and sounds of the simulated environment, but feel, smell, and taste it as well.