Researchers suggest spell checking the spell-checker

In the study, 33 undergraduate students were asked to proofread a one-page business letter -- half of them using Microsoft Word with its squiggly red and green lines underlining potential errors.

The other half did it the old-fashioned way, using only their heads.

Without grammar or spelling software, students with higher SAT verbal scores made, on average, five errors, compared with 12.3 errors for students with lower scores.

Using the software, students with higher verbal scores reading the same page made, on average, 16 errors, compared with 17 errors for students with lower scores.

Dennis Galletta, a professor of information systems at the Katz Business School, said spell-checking software is so sophisticated that some have come to trust it too thoroughly.

"It's not a software problem, it's a behavior problem," he said.

Microsoft technical specialist Tim Pash said grammar and spelling technology is meant to help writers and editors, not solve all their problems.

The study found the software helped students find and correct errors in the letter, but in some cases they also changed phrases or sentences flagged by the software as grammatically suspicious, even though they were correct.

For instance, the letter included a passage that said, "Michael Bales would be the best candidate. Bales has proven himself in similar rolls."

The software -- picking up on the last "s" in "Bales" -- suggested changing the verb from "has" to "have," as if it were a plural. Meanwhile, the spell-check ignored "rolls," which should have been "roles."

Richard Stern, a computer and electrical engineer at Carnegie Mellon University specializing in speech-recognition technology, said grammar and spelling software will never approach the complexity of the human mind.

"Computers can decide the likelihood of correct speech, but it's a percentage game," he said.<