In many schools, the sixth form is a secret garden. Senior leaders often think twice about judging the quality of a complicated lesson on thermodynamics, and the statistical variations produced by small group sizes can provide a smokescreen for underperforming teachers.

But these excuses should hold no weight when it comes to measuring the success of a sixth form. And the effective running of post-16 provision is now more crucial than ever, given the emphasis placed on it under the new Ofsted framework, which came into effect in September. The changes mean that inspectors will be raking over this patch with the same energy and attention to detail that they apply to the rest of a school.

Of course, sixth-form lessons have always been observed by inspectors, but sixth forms now receive a separate judgement. As a consequence, you can expect inspectors to divide their time in proportion to the size of your sixth form: if it has a quarter of the school’s students, it is likely to have a quarter of the lesson observations.

The rating achieved is not necessarily limiting for your school: for example, a “requires improvement” for the sixth form does not mean the overall judgement will be the same. Nevertheless, inspectors will be balancing their findings. If teaching in a quarter of a school requires improvement then it might be possible for the school’s overall teaching to be judged good, but it is unlikely to be outstanding. Similarly, how can school leadership be good if it allows a quarter of students to experience teaching that requires improvement?

So, effective preparation for sixth-form inspections is imperative. Below are my tips on how to get it right.

Apply the same standards

All your school’s systems - training, monitoring, literacy guidelines, marking policies, student voice, performance management and so on - must explicitly apply to the sixth form, too. CPD sessions are often followed up with monitoring visits to lessons for Years 7-11 but not beyond. Likewise, your school may conduct rigorous checks of marking in Year 11 books but not Year 13. But if you exclude your sixth form in this way, the message to staff is clear: the expectations are not the same.

Get the data story right

As ever, the inspectors will start with data. They have access to reports and will scrutinise success and retention rates. Fortunately, they will also look at other evidence if you provide it, so use your systems to tell your story.

Make sure you cover all the issues raised by the data. For example, if students are doing AS courses but dropping out at A2, what does this suggest about your information and guidance processes? The data might indicate that students from low starting points are not achieving well. Is your curriculum appropriate? Are there enough vocational options?

Take retakes seriously

In line with current national priorities, inspectors are paying close attention to post-16 students who are still working towards C grades in their English and maths GCSEs. The days of after-school retake classes with no one checking attendance or the quality of teaching are long gone. If you are not monitoring progress in these classes with the same rigour as you apply to Year 11, you need to start now.

Ensure teaching is not just academic

There is a new focus on students’ preparation for life in modern Britain - inspectors are investigating how well sixth forms develop young people’s personal, social and employability skills. We know inspectors are not looking for specific styles of teaching. On the other hand, a teacher who simply replicates the style of her old university lecturer might be imparting knowledge but not developing social skills. Consider how well teaching styles differentiate for various ability levels.

Step into the inspector’s shoes

What clues does a file of notes offer about students’ achievement and wider skills? What might the inspector be tempted to deduce if the file contains only a few scrappy sheets and a squashed chocolate biscuit? Other rich sources of evidence are the study room and the common room: how well are students using them? Take the time to see your school through an inspector’s eyes.

Roger Pope is principal of Kingsbridge Community College in Devon