The Trust has also announced it will begin a longer-term policy review into how and when the BBC should use premium rate phone lines and associated programme interactivity, following a report commissioned by director general Mark Thompson.
The BBC's former director of news and current affairs, Ronald Neil, will lead the policy review.
Thompson said: "This report is the outcome of a rigorous review by Jana Bennett, director of BBC Vision. Whilst it reveals serious errors of judgement by two BBC programmes, its scrutiny of the use of premium rate telephony by more than 200 BBC programmes found no evidence of systemic abuse or failure."
Sir Michael Lyons, BBC Trust chairman, said it was the Trust's role to put in place guidelines which reflect the public's high expectations of the BBC.
"When the BBC falls short of those expectations and breaches occur, as happened on editions of 'Blue Peter' and 'Saturday Kitchen', it is not surprising that licence fee payers feel let down and disappointed," he said.
'Blue Peter' was singled out for intense criticism earlier this year, after 14,000 children viewers called in to a competition that was won by a member of the studio audience. At the time, the BBC said the incident was because of a phone-line fault.
The Trust expects the review's recommendations in autumn.
"We will draw on those, together with the findings and reports from Ofcom and Icstis as they relate to the BBC, and work emerging from the BBC management's working party on the use of premium rate telephony, before we publish the Trust's conclusions," Lyons said.
Several television programmes have been linked to phone-in competition scandals this year, including Channel 4's 'Richard & Judy', ITV1's breakfast show 'GMTV' and ITV's 'Dancing on Ice'.