Educating Cardiff (Channel 4, 9pm)

THIS series may be about to suffer the law of a diminishing returns having followed an award-winning visits to Yorkshire and Essex, plus the East End of London. Cardiff is next with the cameras trained on Willows High School, in the city's Tremorfa area.

This time we're following the progress of pupils from year seven through to 11, as well as its staff, which is a mix of newly-qualified teachers and old hands, all led by head Joy Ballard.

She took over in September 2011, and a year later, the school was rated unfavourably in an Estyn report, which stated that it needed "significant improvement". However, this is an area where there are multiple social and economic disadvantages. Almost two-thirds of its pupils live in some of Wales' most deprived streets. Things are, however, looking up.

"I think that the children at my school are remarkable and with the support of our outstanding staff manage to get past the barriers that hold them back such as low self-esteem, low aspirations and deprivation factors that put them at a disadvantage to others," says Joy, who is going to be the centre of attention over the coming weeks.

"I believe that they will be positive role models to other young people which might help them get through tough times in their lives."

She claims that everybody involved in the school loved the idea of opening its doors for Channel 4's cameras, and she spoke to Jonny Mitchell from the Yorkshire programme about what the filming experience was like.

"I was initially worried that the series could be edited to show the children in a bad light. They usually do ten times more good than bad. They're just kids, they mess up, we put them right and they trust and appreciate us. The producers convinced me that they would show all of the stories they followed about individual pupils right the way through to their conclusion."

Amazingly, Joy claims she had never seen any of the previous Educating series before the thought of participating came up. But she did shows a clip of Musharaf in Educating Yorkshire overcoming his speech barriers with the help of an inspirational teacher.

"I showed it to our pupils in assemblies – we all cried together. Before deciding to be the next school I watched all of the previous episodes."

Joy comes across as a bundle of energy, somebody who is fiercely proud and protective of the 700 pupils and 100 staff in her care. She is also ambitious for the future.

Tonight we meet aspiring actress Leah, who has one of the school's worst attendance records, and Jess, who never misses a day, is a hard worker and can't understand why her fellow pupils misbehave.

New Tricks (BBC1, 9pm)

TED leads an investigation into the apparent suicide of a city trader who was embroiled in the cut-throat world of London's financial district in the 1980s. As the team delve deeper into the macho fraternity of "The Wolfpack", they find a darker side to the debauchery, secret hand signals and all-nighters that bonded the traders together – including a strict hierarchy that might be worth killing for. Meanwhile, Steve tries to learn some tricks of the trade, amid his own financial crisis. Detective drama, starring Larry Lamb.

Fried (BBC3, 10.30pm)

AS BBC3 continues to live on borrowed time (well, borrowed transmission time because it's supposed to be heading online), here comes yet another attempt to find that elusive ratings winner of a sitcom. It comes from brothers Harry and Jack Williams, who created the abducted child mystery Missing, and may well tick the "crude and silly" box for the average viewer. This is set in the struggling branch of a fast-food chain, it focuses on the establishment's disgruntled staff who refuse to be encouraged by their eternally optimistic manager. The opening episode sees her go undercover in an attempt to find out what her staff really think of her. Katy Wix and Matthew Cottle star.