President Obama’s administration has improved in its responsiveness to Freedom of Information requests, but still has a ways to ago, according to a new report on the issue.

Of 90 federal agencies equipped to process requests made under the Freedom of Information Act, slightly more than half have taken at least some steps to fulfill Obama’s goal to improve government transparency, according to the study by the National Security Archive at George Washington University and the Knight Foundation. The report is set for release Monday.

Researchers submitted FOIA requests to each agency seeking information on any changes made since Obama ordered the government to “adopt a presumption in favor” of FOIA requests on his first full day in office in January 2009.

Though 49 agencies and departments complied with the study’s authors, 17 others — including the Transportation Department and U.S. Postal Service — provided no documents and two withheld information. Another 17 agencies — including the departments of Commerce, Energy, Justice and State — provided no final response, and four smaller agencies never acknowledged receipt of the FOIA request. The figures have improved significantly from last year, when just 13 of 90 agencies complied.

“At this rate, it’ll be the end of his term before the agencies do what Obama asked them to do on the first day,” said Thomas S. Blanton, director of the National Security Archive.

The report’s publication coincides with the start of Sunshine Week, an annual effort by news organizations and good-government groups to raise awareness about improving access to public information.

As part of the week’s events, the Obama administration on Monday plans to launch FOIA.gov, a site meant to inform the general public on how to request government information. The site is one of several established by the Obama White House to give better access to government data and spending information.

Administration officials disputed some of the report’s conclusions, noting that when taken as a whole, the government at least partially fulfilled 93 percent of all FOIA requests reviewed in fiscal 2010, a significant increase from the previous year. Collectively, federal agencies cut their backlogged FOIA requests by about 10 percent in fiscal 2010, according to White House officials.

The study credits agencies with fulfilling more requests for drafts and final copies of internal documents and staff-level reports. Federal FOIA law permits agencies to withhold such “pre-decisional” or “deliberative process” information — the type of data that transparency advocates believe is essential to truly understanding the mechanics of government.

Ten of the 14 Cabinet agencies have cut their use of the “pre-decisional” exemption, according to the White House.

“This is the kind of window that can actually bring some real accountability to the policy process, and that could be the most significant impact of Obama’s changes,” Blanton said.

House Republicans are also planning to probe the administration’s responsiveness to FOIA requests.

Rep. Darrell Issa (R-Calif.), chairman of the House Oversight and Government Reform Committee, asked agencies in January to turn over information on the number of requests received in the last five years. He also plans to investigate the government’s public reporting of spending information, another key element of Obama’s transparency reforms.

Steven P. Croley, who oversees a team of White House staffers responsible for ethics issues, said several departments made significant improvements in the last year by staffing up, retraining workers or simplifying the review process.

Among others, the Agriculture Department, Environmental Protection Agency and Consumer Product Safety Commission are preempting FOIA requests by publishing online government data sets previously withheld from public view.

“It’s not a kind of change that you can dictate in one day, there’s no switch to throw that’s going to change FOIA practice overnight,” Croley said in an interview. “But from a realistic standpoint, have agencies focused on FOIA, have they made it a priority, are they taking more time to figure out where we can disclose information? Yes.”