Pew Research Center

Only 27 percent of people surveyed by Pew researchers correctly identified Brian Williams when shown a picture of the NBC anchor, Pew reports. Older Americans were far more likely to recognize Williams than people under 30: 34 percent of those over 65 knew who he was, while only 15 percent of those under 30 did.

By comparison, when Times Mirror/Gallup asked the same question in 1985 about Dan Rather, 47 percent of people overall recognized the CBS anchor, who like Williams was the top news anchor in the country at the time of the survey. In 1985, 41 percent of those under 30 knew who Rather was by his photo.

Williams is the guy on the left. (AP Photo/Charles Sykes)

Pew says the data "reflects a large decline in the audience for nightly network news since the 1980s."

For example, in November 1985 an average of 48 million Americans watched one of the network newscasts each evening. By 2013, that number had fallen to 24.5 million, according to Pew Research analysis of Nielsen Media Research data.

Some interesting data in the topline: 2 percent of those surveyed identified Williams as Vice President Joe Biden. One percent thought he was former presidential candidate Mitt Romney, and 53 percent had no answer.

Correction: Due to an editing error, an earlier version of this story mistakenly identified Williams as a CBS anchor.