Rare is the scientific paper today written by a single author. With research being conducted by teams of scientists, most studies now boast a half-dozen or so authors. According to a new study led by a scientist at the Oklahoma Medical Research Foundation, credit for those papers is far from evenly distributed, and the order in which the authors' names are listed makes a big difference.

The new findings appear in the Nov. 1 issue of the scientific journal EMBO Reports. OMRF's Jonathan Wren, Ph.D., is the first author on the paper, which is entitled "The write position."

In scientific circles, the long-accepted hierarchy of authorship places the one who did the lion's share of the work first and the senior author last. "What we wanted to know was: What about everyone in between?" said Wren. "What do people think about the middle authors and their contribution to the work described in the paper?"

To find out, the researchers mailed surveys to promotion committees at 142 medical schools in the United States and Canada. Sixty-six percent of the U.S. schools responded to the questionnaires, while 28 percent of the Canadian schools replied.

Those survey results revealed that when an author's name appears in the middle, rather than the beginning or end, of a byline on a scientific paper, their perceived role in the project diminishes quickly. That can mean that, even when the publication appears in a prestigious journal, authors receive little credit (and, consequently, diminished chances for promotion, research funding and tenure) when they are listed as one of several middle authors on a paper.

As the number of authors per paper grows, the roles of authors listed in the middle increasingly blur. "Researchers define or rank authorship position subjectively, and there are few clear-cut standards," said Wren. "Our survey results showed that author names appearing near the beginning of the list of authors are perceived to have contributed more to the project." Senior authors - those listed last - tend to maintain their standing no matter how many authors are listed in the byline.

"All authors deserve fair credit, wherever their names appear," said Wren. "We hope this study gives authors, editors and committee members a better understanding of the trends and of how perceptions about scientific contribution are formed."