Don't assume common knowledge

I just returned from a cross-country trip, and found this in my email, via Newswise:

Some people face their biggest problem with communication when sharing new information with people they know well, newly published research at the University of Chicago shows.

Because they already share quite a bit of common knowledge, people often use short, ambiguous messages in talking with co-workers and spouses, and accordingly unintentionally create misunderstandings, said Boaz Keysar, Professor in Psychology at the University of Chicago.

“People are so used to talking with those with whom they already share a great deal of information, that when they have something really new to share, they often present it in away that assumes the person already knows it,” said Keysar, who with graduate student Shali Wu tested Keysar’s communication theories and presented the results in an article, “The Effect of Information Overlap on Communication Effectiveness,” published in the current issue of Cognitive Science.

“Sharing additional [new] information reduces communication effectiveness precisely when there is an opportunity to inform—when people communicate information only they themselves know,” the researchers said.

In real life situations, the assumptions people make about what another person knows have many consequences, Keysar said. Doctors, for instance, often communicate quickly with each other and miscommunicate because they don’t realize the other physician is getting new information when they are discussing a treatment program, he suggested.