Public interest groups accounted for just 4 percent of total sources. General public—"person in the street," workers, students—accounted for only 14 percent, while current and former government and military officials totaled 50 percent of all sources.

Male sources outnumbered women by more than 4-to-1 (82 percent to 18 percent). Moreover, 72 percent of US guests were white males, while just 6 percent were women of color.

People of color made up only 15 percent of US sources. African-Americans made up 9 percent, Latinos 2 percent, and Asian-Americans and people of Mideastern descent made up one percent each. Alberto Gonzales accounted for more than 30 percent of Latino sources, while Condoleeza Rice accounted for nearly 13 percent of African-American sources.

Among partisan sources, Republicans outnumbered Democrats on the NewsHour by 2-to-1 (66 percent vs 33 percent). Only one representative of a third party appeared during the study period.

At a time when a large proportion of the US public already favored withdrawal from Iraq, "stay the course" sources outnumbered pro-withdrawal sources more than 5-to-1. In the entire six months studied, not a single peace activist was heard on the NewsHour on the subject of Iraq.

Segments on Hurricane Katrina accounted for less than 10 percent of all sources, but provided nearly half (46 percent) of all African-American sources during the study period. Those African-Americans were largely presented as victims rather than leaders or experts: In segments on the human impact of the storm, African-Americans made up 51 percent of sources, but in reconstruction segments, whites dominated with 72 percent of sources; 59 percent of all African-American sources across Katrina segments were general public sources.