Online move 'to cost BBC3 viewers'
The man in charge of BBC TV says he expects to lose viewers when BBC3 moves online.
The plans for the channel, subject to approval by the BBC Trust, would see it close and move completely online next autumn.
That is expected to save £50 million, and the vast majority of the new, smaller budget - 80% - will go on traditional comedy and documentaries, while 20% has been set aside for short films and digital media designed to draw in young viewers from sites including Tumblr, YouTube and Twitter.
It will also allow the corporation to launch a BBC1 +1 channel and show two hours more of CBBC a night.
Mr Cohen told reporters: "We expect an initial drop overall and that's why we want BBC1 and BBC2 to pick up the weight. It's also why we see this as a package in our proposal to the trust for a BBC1 +1, because we know those +1 channels are very important to people."
He said the BBC needed "to learn, fail, learn again, innovate and succeed" to cope with the changing landscape where more people watch TV on computers and phones.
Damian Kavanagh, who is in charge of putting the plan together, said: "This 80/20 mix would extend and enhance the BBC3 experience and be of the moment, giving audiences more.
"It's a radical change for a TV channel to propose committing such a significant amount of its budget to non-TV content but I believe this will lead to greater innovation and allow us to engage with audiences for longer and more depth than ever before."
He said programmes would be divided into two strands, called "make me laugh" and "make me think", concentrating on comedy and documentaries.
The decision to move the channel is a controversial one - ab out 187,000 people signed an online petition opposing the move less than a week after the decision was made public.
Jono Read, one of the organisers of a campaign to save the channel, said the announcement "left a lot of questions still unanswered".
He said: "The BBC Trust claimed that BBC3 was both diverse and young, and reached this audience better than any other BBC channel. Now the BBC admits it will see a drop in these audiences when it moves online.
"Why allow this audience to move elsewhere, and what happens if there's a significant drop? Will the BBC have a Plan B?
"We know that not everyone can get television online because of issues with broadband provision, particularly in rural areas, and the BBC is launching a BBC1+1 for that very reason, but for young people it's made the decision to take that content off our screens altogether. This somewhat defies logic."
Mr Cohen did not go into detail about which programmes would survive the move but the emphasis on comedy and documentary would seem to signal the end for entertainment shows including Don't Tell The Bride and Snow, Sex And Suspicious Parents.
Mr Cohen said: "We've spoken to many viewers and organisations for whom online content is already a major part of their media consumption.
"While it would be naive to suggest there wouldn't be a loss of viewers initially, we believe today's proposal will position BBC3 well with younger audiences in the long term. This is a proposal for the future."