Why do some stories disappear after just one mention? Occasionally, stories get reported on the news and then suddenly get dropped from the agenda. That can puzzle, and sometimes annoy, viewers and listeners.
Breakfast failed to update viewers on an apparent plane crash
An example occurred on Breakfast one morning recently, when the programme reported that a plane had crashed at Nairobi airport in Kenya. But after the initial report, nothing more was said about the plane crash.
In fact, there hadn't actually been a crash. It turned out that an emergency drill was so realistic that the local media reported it as a real accident. But shouldn't that information have been passed on to viewers?
Viewer David Farr had been expecting friends from Kenya and was angry that he was left in the dark.
"I can understand that you can get false information like that, particularly from a third world country, " he told NewsWatch. "But when I phoned the Beeb they told me that by quarter to nine (that morning) they knew this was just a drill. So there was no confusion there and still it wasn't mentioned on the TV at all - and that I find unacceptable."
Breakfast editor David Kermode accepts the criticism. "What we weren't absolutely clear on when we started getting the reports that it was a drill was whether it was a drill that had gone horribly wrong - i.e. that there had been a plane crash during the drill - or whether there was actually just a drill that was very, very convincing.
"Clearly what we should have done and didn't do was follow up and say, 'You may recall, we brought you this news 10 minutes ago. .. in fact this is an emergency drill taking place at that airport."
Mr Kermode believes the culture in the BBC newsroom is changing. "We know that our viewers get frustrated when stories are just allowed to drop."
Audience expectations too are changing, according to research conducted by the BBC - as explained by Helen Boaden, the director of BBC News, to the News Xchange international broadcasting conference in Amsterdam last November.
"When stories are unfolding the real trick is to share what you do and don't know with your audience. The audience is very sophisticated these days. We've just done a chunk of audience research across the whole of news and one of the things that's emerged for us is that in our built bulletins on BBC One, the audience expects a spectacularly high level of accuracy, and they're quite right to want that. And they're very unforgiving when we get things wrong in those bulletins.
"When it comes to News 24, they are more sophisticated about the nature of breaking news than we've given them credit for and they're very well aware that stories unfold and information changes."
David Farr agrees with the view that viewers like himself are becoming more forgiving about rolling news. "Anybody can make a mistake or get false information. But when they get a correction on that they should pass it on to the viewers - it's essential."