Here is how The Real School’s Guide collated their information...

The unique rating system uses 50 different measures, put together from the latest publicly-available data and broken into four categories - attainment, progress, attendance, and outcomes.

National league tables may only look at overall GCSE results, as well as newer measures. Attainment

This is worth 30 per cent of the total score. It is based on pupils’ average grade attainment score, including what the average scores for different groups of pupils were, as well as the proportions gaining the English Baccalaureate and those getting A* to C grades in GCSE subjects. It measures whether a school is getting top marks, and if it is managing to improve year-onyear.

Progress

This is worth 40 per cent of the score. It is based on how well different types of pupil do in terms of progressing. It also looks at things that may contribute to teaching outcomes, such as how big the pupil/teacher ratio is in comparison to the national average, as well as teachers’ average salaries.

Attendance

This score is based on absence rates, looking at both overall levels of sessions missed as well as unauthorised and persistent absence at the school. It is worth 15 per cent of the total score.

Outcomes

This is also worth 15 per cent, and is based on what proportion of pupils continue with education after Year 11 or go on to training and work.

■ Schools that had no Year 11 pupils taking GCSEs in 2017 are not rated.