Most teachers like to think of themselves as amateur psychologists. After all, you don't stand in front of a class, day in, day out, without learning a thing or two about what makes young people tick.
But the professionals do things differently. Educational psychologists take a scientific approach - through testing, measuring and research - and use their findings to ensure children are being taught in the best possible way.
Ed psychs or EPs are probably best known for their role in assessing children with special needs. But there's more to the job than diagnosing dyspraxia or attention deficit disorder.
A child hit hard by bereavement; a bully striking out in the playground; a gifted pupil whose confidence has been knocked - whatever the scenario, an educational psychologist should be able to get to the root of the problem and offer solutions.
Most educational psychologists are employed by local authorities as part of the children's services department. "EPs look after a small group of schools and visit them all regularly, not just when there's a problem," says Dr Michael Hymans, head of the educational psychology service in the London borough of Brent.
"It's about providing the kind of service schools want. That might mean helping them to develop effective anti-bullying or behaviour policies. Or working with groups of pupils informally to tackle issues such as motivation. It's not all about assessment."
It used to be possible to make the leap from teaching to educational psychology quite quickly, which explains why many EPs are former teachers.
These days it's a longer transition. You generally need a first degree in psychology, after which you have to complete a three-year doctorate programme. But the last two years of the doctorate are placement based, so you'll be working in a local authority - and getting paid.
Despite the fact that retraining is a lengthy business, Dr Hymans says plenty of teachers make the switch. But getting on to the three-year programme can be tough - with as many as 10 applicants for each place.
On the plus side, if you do get accepted on to the course, finding a job at the end should be relatively straightforward, with EPs currently in high demand in most parts of the country.
Alex Griffiths was head of science at an east London school before retraining as an educational psychologist over 30 years ago. "I just felt drawn to it," he says. "I wanted to work with individuals rather than classes because it gives you a real chance to understand behaviour and effect changes."
After many years in a local authority, Mr Griffiths now runs EGS, a company that provides educational psychology services to independent schools, as well as maintained schools looking for something different.
Among other things, EGS helps teachers to develop more effective literacy and numeracy programmes. "We try to bring a psychological angle to the curriculum," says Mr Griffiths. "For example, we explore ways of making praise and encouragement integral to teaching.
"This is a wonderful job. Educational psychology is under-valued centrally and the possibilities are still not being fully exploited - but on a day- to-basis, I love every minute of it. I'm over 60 now but have absolutely no intention of giving up."