The National Association of Broadcasters, in partnership with the state broadcast associations, commissioned a research project among television and radio station broadcasters throughout the United States and the District of Columbia to determine the extent of station participation in community service activities between January 1, 2005, and December 31, 2005.

The scope of the project included all full-power commercial radio and television stations in the United States. Broadcasters representing a total of 625 television stations completed the census, as did broadcasters representing 4,502 radio stations, for a total of 5,127 stations responding. The overall response rate for this project was 44.4 percent (5,127 of 11,540 commercial broadcast stations). The completion rate among television stations was 54.0 percent (625 of 1,158 stations), and among radio stations it was 43.4 percent (4,502 of 10,382 stations). This is an excellent return rate for a project of this type; even when targeting an association's own members, most mail surveys tend to fall in the 20 to 30 percent response range.

The margin of error for the overall percentages reported is ±1.02 percent at the 95 percent confidence level. That is, if this census were to be replicated 100 times, we would expect the true percentage of the population to fall within a 1 percent statistical interval at least 95 times. For the television sub-sample, the margin of error is ±2.66 percent; for the radio sub-sample, it is ±1.10 percent.