It is report-card season for US science agencies, and the grades are in on their media skills. The Union of Concerned Scientists, an advocacy group based in Cambridge, Massachusetts, has ranked the public-relations policies of 15 federal organizations.

It gave the highest marks to the Centers for Disease Control and Prevention in Atlanta, Georgia, whose written policy allows scientists to express their personal views. NASA also fared well, earning a "B" for its policy and a "satisfactory" for its practice. The Environmental Protection Agency (EPA) finished near the bottom of the class — its lack of an agency-wide policy earning it a "D".

The group says that the grades will help the next president to reduce the censorship of government scientists, but EPA spokesman Jonathan Schradar called the grades "nothing more than continued petty politics".