Few heads today have the luxury of taking a long, slow look at a large field of candidates and inviting a chosen few in for a day of interviews.

As finding staff becomes increasingly difficult, heads often snap up a good candidate on the strength of a half-hour meeting. While the head sighs with relief at filling the vacancy, the appointed and breathless teacher can be left desperately hoping this is the right job.

At least some of the doubt can be avoided with an informal visit to the school before the interview. After all, most of us would be loath to make a big purchase, such as a house or car, without extensive research. Yet when it comes to job hunting we don’t look much further than the advertisement, even though the decision is life-changing.

If you look before you leap, you can avoid those big holes in the ground, as French teacher Kerry Hill would agree.

After a bad experience early on in her career, Mrs Hill would not apply to a new school now without first making an informal visit. “After my teaching practice in one of the toughest comprehensives in Leeds, I’d decided I’d be better suited to teaching in a private school,” she recalls.

“I knew it would probably be more difficult to get a languages job in the private sector, so I couldn’t believe it when I got an interview for the first job I’d applied for at a very successful London school. When I was offered the job, I was thrilled.

“At the time, I felt uneasy about the interview process: I was only at the school for 45 minutes and didn’t get to meet anyone apart from the headteacher, or have a tour of the school. But I was so pleased to be offered the job, I pushed my reservations to the back of my mind and signed a contract.”

The doubts resurfaced about a week later, when Mrs Hill was flicking through a publication from her teaching union. She spotted a small notice asking anyone who had applied or was considering applying to the school to get in touch. A phone call to the union confirmed her niggling uneasiness.

“They said the headteacher had a reputation for bullying and intimidation,” she said. “This was also suggested by the staff turnover: the previous four French teachers had left suddenly or been signed off with stress-related illnesses. No wonder she hadn’t wanted me to meet any of the staff or students.”

After hearing the news, Mrs Hill had the messy job of telling the head she no longer wanted the job and breaking the contract she had signed.

“It all got very complicated,” she says. “It certainly taught me a hard lesson. I did manage to secure a post at the local comprehensive, where I’ve been very happy. Now I’m ready to move on, but this time I’ll remember that it’s not just that they are interviewing me; I’m interviewing them too.”

Peter Brown, headteacher at Top Valley secondary school in Nottingham, agrees. There has been a change in the purpose of the pre-interview visit, which used to be simply an extra chance for applicants to shine.

“These days, when schools - particularly city schools - often struggle to get a decent interview field, we are very much aware that it is just as important for us to impress potential applicants, as for them to impress us,” he says.

Mr Brown is always happy to arrange informal pre-interview visits, led by him or a deputy, and believes that meeting applicants informally can be an ideal opportunity to make them aware of the context and ethos of the school.

“In the case of Top Valley, they have to be ready for the challenge. They need to know what they could be letting themselves in for,” says Mr Brown, 17 per cent of whose pupils have special education needs.

“A school that is open and self-critical is likely to be good one. Any attempt to hide information or aspects of school life should be treated with suspicion. We all know that schools are increasingly busy places, but a good leadership team will make the time to welcome potential applicants.

“They will be happy to provide you with opportunities to speak to staff and students and share details about induction programmes, professional development and support structures.”

An informal visit can be particularly helpful for teachers seeking management positions. When primary school teacher Sarah Gradley started to apply for deputy headships, she visited several schools advertising suitable vacancies.

“Taking up a management post is a huge commitment. I wanted to make sure I was making the right decision. At interview, you can be so caught up with nerves, you sometimes miss the obvious or forget to ask important questions. Experiencing a school in a more relaxed context is so much more useful,” she says.

“At one school I visited, I noticed the displays hadn’t been changed for months and some of the classrooms were very untidy, which didn’t suggest great investment in the students. At another, I felt the atmosphere in the staffroom was very frosty. You can’t expect every job to be perfect, but at least if you’re aware of potential problems, you can decide whether you want to take them on.”

A visit can tell you more than the information pack or an inspection report about whether you will be happy in a school. And it gives you a good basis for those intelligent questions you’ll be asking at the interview.

As Mr Brown puts it: “When you apply for a job, you have to know what you’re dealing with and the school has to be right for you. It’s far too important a decision to leave to chance.”