The accuracy of a controversial set of rankings of doctoral programs by the National Research Council has been questioned since their release in September 2010. Now, two waves of corrections issued last month in response to criticism have boosted the ranks of several of Yale’s graduate programs.

The NRC, which is part of a private, non-profit institution known as the National Academies that operates under a congressional charter to provide policy advice, used data from the 2005-’06 academic year to rank about 5,000 graduate programs across the nation. The two sets of alterations, released last Friday and April 21, correct simple input errors as well as methodological problems. The adjustments have caused most programs to move just slightly in the rankings, according the Chronicle of Higher Education.

Professors at universities around the country, including Yale, have called the NRC data outdated and claimed that some of its information is inaccurate. Julia Adams, chair of the Sociology Department, told the News in March that the number of sociology faculty members reported by the NRC was “wildly off-base.” Erroneous faculty counts are not addressed in the recent changes, nor is the exclusion of book-length publications from overall publication counts in the social sciences.

The Yale University Office of Institutional Research raised questions about the NRC data for the percentage of Yale students who finish their degrees within six years, said Charlotte Kuh, deputy executive director of the policy and global affairs division in the NRC. The NRC found that it had incorrectly entered figures for seven of Yale’s graduate programs, including applied physics, astronomy, biomedical engineering, cell biology, cell and molecular physiology, chemical engineering and chemistry. The recalculation slightly improved Yale’s rankings in each of the fields except chemistry, which saw a slight drop, Kuh said.

But the movements in ranking will not have much of an effect on how Yale views its programs, said Richard Sleight, associate dean of the Graduate School.

“I don’t think the NRC corrections will have a big impact at Yale,” he said. “My sense is that the [NRC] results are not at the forefront of our faculty’s thoughts these days.”

In the first round of corrections, the NRC acknowledged that it had undercounted honors and awards and the percentages of students who find academic jobs, according to the NRC corrections log. The NRC also corrected problems with its calculation of financial support for first-year students and its information about certain publications in the non-humanities fields. The changes to Yale programs’ six-year completion percentages were included in the corrections released April 21.

The second set of corrections, which were released Friday, made less sweeping changes. The NRC corrected the statistics for time to degree and eight-year completion rates for art history programs and placed N/D (no data reported) for the percentages of faculty members with tenure for all of Harvard University’s programs.

The NRC data includes characteristics such as student GRE scores, program size and faculty composition.