In 60 or so schools around the country, as far apart as East Sussex and Rochdale, something has made even this “seen-it-all-before” commentator sit up and smile. It’s called the “expert trail” and it’s professional development for teaching assistants and admin staff. It isn’t easy to explain, but then, says Derek Lovell at Telscombe Cliffs primary in East Sussex, on his third headship and with more than 30 years of teaching behind him: “Everything valuable that I’ve come across in teaching has been difficult to explain.”

The basics are clear. The trail provides a structure that defines, recognises and celebrates achievement in professional study chosen by the staff member. Developed as a school improvement tool by Dame Sheila Wallis, when she was head of a school in Worthing, expert trail is now promoted to authorities and schools by Dame Sheila’s consultancy, the Wallis Partnership.

That’s the quick explanation, but to get at what makes it exciting, you have to meet some of the people who are on the trail.

Take Gail Manning, a teaching assistant at Telscombe Cliffs. When the school became one of 10 in the county to take on the expert trail, she was deeply nervous. Very capable in the classroom, she shrank from anything apparently more exposed.

“I didn’t feel I was a very confident person,” she recalls. “I didn’t actually want to start on it because of how I felt about myself.”

However, with support and encouragement Gail chose to develop her knowledge of Numicon, a popular multi-sensory approach to learning number used in her school. She contacted Numicon’s authors, and set about deepening her understanding through training and school visits. Now she’s regarded as an authority on Numicon in her school and beyond. She even features in a Numicon training video.

What really strikes Derek Lovell and his colleagues though, is the transformation in Gail, who is now able to talk with authority on her specialism. It’s that surge in professional confidence, together with the bonds forged by shared endeavour, that makes the expert trail so exciting.

I found the same enthusiasm in Rochdale, where expert trail was seized on two years ago by the then newly-constituted Real (Rochdale Education and Learning) trust, set up by schools to handle professional development in the authority.

Dave Kendell, head of Shawclough primary, one of Rochdale’s first group of user schools, is clear about why it is so successful. “When I heard about it I realised we were doing professional development to teachers. Instead, teachers should be in charge of their own professional development, and the expert trail framework gives that opportunity.”

Judith Talbot, a teacher for more than 30 years, and early- years leader at Shawclough, agrees. “We used to have professional development on Tuesday evenings, one-size-fits-all. Now instead I’ve been able to develop my own interest in children’s emotional development. I’ve studied the Reggio Emilia approach (named after the early-years centre in Italy) and (experiential education expert) Ferre Laevers.”

Judith’s commitment has attracted the attention of Rochdale, and the authority has entered her on a two-day course to study the Laevers approach for them.

“It’s not good enough just to ask where’s my next lesson coming from?” she says. “There’s a need to know not just what we’re doing, but why we’re doing it.”

Wherever expert trail is used you find keen people, motivated and energised through the pursuit of a specialism that’s close to their hearts, supportive of children’s learning and valued within their schools. So at Telscombe Cliffs, as well as Gail Manning, there are those, like teaching assistant Zoe Cox, who’s investigating the use of British Sign Language with hearing children, and teacher Sonia Clarke, spending a year developing her expertise in dyslexia. Every adult, in fact, is following the trail where it leads.

It may seems a bit random, or even self-indulgent, but that’s exactly what it’s not. For one thing the expert trail is highly structured - robust and applicable to any school or setting. There are five defined stages, supported by a professional learning mentor - normally a senior member of staff. At the end of each stage there’s a progress review.

Each person’s focus is agreed at an initial interview, and is clearly linked to the school’s improvement plan. That, as much as anything, is what attracts those responsible for professional development in their authorities.

Martine Sinker, Real Trust’s headteacher co-ordinator says: “It fits so many requirements - threshold standards evidence, performance management targets. Ofsted approves of it. It gives structure and form to CPD. It’s about strengths, and it’s motivating.”

While it’s rather early to assess its impact on pupil achievement, Nina Siddall of CfBT (providers of CPD in East Sussex) says: “If you have staff happy and positive, if they’re better at what they do, then the effects on the children are indisputable. It’s learning from the best to improve the rest,” she says. “All the answers are out there.”

That, it seems, is the nub of it. Derek Lovell says: “At the start I said to the staff that although we’ve talked about being a learning school, actually we’re pretty poor at it. We weren’t giving staff the opportunity to do their own kind of learning except in a hit-and-miss way. I told them this was something that would give everyone an opportunity.”

For Dame Sheila, that’s always been the vision. “It switches teachers on to learning,” she says. “It’s saying that everybody in this school is a learner, and everybody is also a teacher.”

www.wallispartnership.co.ukwww.numicon.com. Professor Ferre Laevers is at the centre for experiential education, Leuven, Belgium. www.cego.be