We think we're so funny. But when we try to have clever conversations via electronic mail, often recipients don't hear it quite the way we meant it -- and that can lead to miscommunication.

A study published earlier this year in the Journal of Personality and Social Psychology found the tone of an e-mail missive, whether it be straight or sarcastic, only came through accurately a little more than 50 percent of the time in an experiment using college students.

But the senders expected to be understood more than three-fourths of the time, and the readers thought they read it right 90 percent of the time, according to the Journal article.

"People routinely overestimate how well they can communicate over e-mail, we offer, particularly when the meaning of the message is ambiguous," wrote Justin Kruger at New York University, Nicholas Epley at the University of Chicago and Jason Parker and Zhi-Wen Ng, of the University of Illinois at Urbana-Champaign.

The problem, said the researchers, is e-mail users feel as if they are having a conversation, but the body language, the gestures, the voice clues that complete a story around the water cooler are missing from text sent by computer. The person writing can hear the discussion in his head so he has a hard time looking at the words as if he were coming at them cold.

In their report, the researchers described a case in which a psychologist sent an e-mail to colleagues announcing an event in honor of a job candidate. After describing the details of food and drinks, she added that "talking to the candidate is not required; just don't embarrass us."

That last part was meant to be sarcastic but some recipients thought she was honestly worried about their behavior.

In 1990, the dark ages before e-mail was quite so prevalent, another researcher documented a similar effect through a music tapping study in which participants tapped the rhythm of a well-known song for a listener. Tappers thought listeners would get it half the time when only 3 percent did. Tappers couldn't tune out the music in their heads while listeners were just getting taps.

Warnings about the dangers of e-mail are not new. Employees have been fired for exchanging inappropriate jokes via their company's network, and law enforcement officers have found a lot of useful material in those quick notes dashed off without a second thought.

But even those who aren't committing crimes and who are experienced in the proper use of e-mail may not realize the extent to which their exchanges can be misunderstood. The college students at Cornell University and the University of Illinois who participated in this latest research tended to be quite familiar with the technology.

"To their credit, participants did not assume that their audience would identify all of their sarcastic statements, and thus seemed to realize that their audience did not share their own 'privileged' perspective," the authors wrote. "But nor did they take adequate account of the gulf between their own perspective and their audience's."

The researchers did impose one restriction on the participants that might have helped better communicate the tone. They were not allowed to use "emoticons," those symbols meant to serve as smiley faces or winks. The authors reasoned that people tend not to use those anyway when the sarcasm or humor is "obvious."