Early this year, Mr. Chetty and five other researchers set out to fill this void. They examined the life paths of almost 12,000 children who had been part of a well-known education experiment in Tennessee in the 1980s. The children are now about 30, well started on their adult lives.

Just as in other studies, the Tennessee experiment found that some teachers were able to help students learn vastly more than other teachers. And just as in other studies, the effect largely disappeared by junior high, based on test scores. Yet when Mr. Chetty and his colleagues took another look at the students in adulthood, they discovered that the legacy of kindergarten had re-emerged.

he main reason it occurs, she said, is because students leave high school unprepared for the intellectual rigors of college writing.

student accused of plagiarism came to Mr. Dudley’s office with her parents, and the father admitted that he was the one responsible for the plagiarism. The wife assured Mr. Dudley that it would not happen again.

But these cases — typical ones, according to writing tutors and officials responsible for discipline at the three schools who described the plagiarism — suggest that many students simply do not grasp that using words they did not write is a serious misdeed.

Digital technology makes copying and pasting easy, of course. But that is the least of it. The Internet may also be redefining how students — who came of age with music file-sharing, Wikipedia and Web-linking — understand the concept of authorship and the singularity of any text or image.

“When you’re sitting at your computer, it’s the same machine you’ve downloaded music with, possibly illegally, the same machine you streamed videos for free that showed on HBO last night.”

Salazar took over Interior in January 2009, vowing to restore the department's "respect for scientific integrity."