BBC Trust has told corporation bosses to improve programming on BBC1 and BBC2 within a year after a review found parts of the schedule "formulaic and derivative".

The trust's review of the three networks' service licences found that overall they were "broadly" delivering high quality and popular programming, but added that there was a lack of ambition and creative risk-taking and dearth of "fresh and new ideas".

Viewer research found that parts of the BBC daytime schedule "lacked quality" with too many shows described as "collectable hunting and property". The BBC Trust said it was "concerned" that a "formulaic and derivative" schedule is damaging the corporation's reputation.

The report found that a third of viewers of BBC1, which has a total budget of £1.37bn or 41% of the licence fee, felt that the channel did not deliver good value for money.

"The channel needs … to harness its scale and size by being more ambitious and taking more creative risks in peak time," the report said.

While the report found that BBC2, which has a budget of £575m, to have the highest quality programming of the five main terrestrial channels, it also said there was a need for the channel to provide something "manifestly different from BBC1 even at the risk that BBC2's reach may fall".

"The clarity of BBC2's role as a challenging and distinctive alternative to BBC1 has diminished in the multichannel world," the report said. "Its aim should be to re-establish its position as providing something to audiences which is manifestly different from BBC1."

"Our research shows that audiences demand more from the BBC, with viewers looking for ideas they can't find anywhere else," said Diane Coyle, the BBC trustee responsible for running the review. "The channels have significant influence and appeal, and while plans are already underway to improve daytime output, the [BBC] executive needs to be more ambitious and take more creative risks to satisfy viewers' expectations."

More than 80% of BBC4's programming was rated "original and different" by viewers, but overall the review found that the channel "does not significantly influence wider audience perceptions of the BBC".

"BBC4's challenge is to increase its impact, particularly in its core areas of specialism, and secure a greater reputational dividend for the BBC, while also retaining its distinctive nature," the report said. The trust said it expects management to "sign post and promote" BBC4 content more effectively and continue its commissioning and scheduling collaboration with BBC2.

The report also said that, overall, it needed to work harder to reach some audience groups including viewers in Northern Ireland, Scotland, some regions of England and ethnic minorities.

The BBC Trust, which said that the three channels were "broadly" successful in delivering against their remits, said that it "expects to see signs of audience improvement by the end of 2011 and will consider at that point whether we need to ask for further action from BBC management to address audience concerns".

"We have just agreed with government a tough new licence fee settlement which gives the BBC stability for the remaining six years of the current [BBC] charter," said the BBC Trust chairman, Michael Lyons. "It will present us with some difficult choices. But the trust is clear that within that new settlement, the BBC must strive to further raise the distinctiveness of its programming in order to satisfy viewers' expectations, particularly for the flagship channels BBC1 and BBC2."

The BBC Trust acknowledged that plans have been put in place to improve daytime programming output since its critical interim review was published in July. BBC management has pledged a number of changes including reducing the number of long running factual entertainment shows, boosting original drama and revamping BBC2's early afternoon programming to a "peak repeats zone" to showcase peak-time output for daytime viewers. BBC2 will also see a boost in current affairs programming.

"In the reviews the BBC Trust has asked us to deliver even more fresh and new content to our audiences," said the director of BBC Vision, Jana Bennett. "Programmes such as Wallace & Gromit's World Of Inventions and Five Daughters are clear examples of our renewed commitment to this kind of programming. In daytime we have already made great progress with programming such as Jimmy McGovern's Moving On and Fake Britain and there is more to come with Missing Live and new drama The Indian Doctor with Sanjeev Bhaskar due in the new year."

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