The key to the meaning of life, it turns out, isn’t 42 - despite what The Hitchhikers’ Guide to the Galaxy may tell you. As far as students taking GCSEs are concerned, the magic number is, in fact, 700. 

That, according to new research published just before Christmas, is the number of words they should write in answer to essay questions in order to obtain maximum marks.

The research, by Tom Benton of Cambridge Assessment, shows that the relationship between words and marks flattens out at around 700.

Below 700 will get you a lower grade - almost every candidate who wrote 200 words or fewer ended up with a U (traditionally regarded as a failure) whereas those who wrote more than 700 words did not necessarily get higher marks. The research looked at 5,000 scripts from the OCR GCSE English literature exam in 2014.

The conclusion from the research was that if you write less than 200 words, you haven’t written enough to show off your knowledge, whereas if you write more than 700 words, it is possible that you are being too verbose.

If the same principle was adopted for national newspapers, it could be an interesting assessment of the Guardian and, say, the Sun.

Another piece of research that may have slipped under the radar while you were overindulging with mince pies shows a widening gap between schools in London and, in particular, the North and North East when it comes to the amount of impact a school has on a pupil’s performance.

Research by the Education Policy Institute, an education think tank headed by former schools minister David Laws, shows that 16 of the top 20 authorities with the best record in improving a pupil’s performance while they are at secondary school are in London. They include areas coping with a high level of deprivation among students, such as Camden and Brent.

The worst performing areas on this measure are Blackpool and Hartlepool - with a cluster of authorities (including some from the Midlands), not far behind.

Mr Laws was quick to mention that initiatives such as academisation and the introduction of Teach First were pioneered in London, which he said may be a key reason for the widening gap.

However, it cannot be the sole answer: Teach First is now operating in other areas of the country (although perhaps not on as large a scale as in London), and the drive towards academisation is now nationwide.

Another answer may be resources; money was ploughed into the London Challenge under Labour to kickstart these initiatives.

Yet another could be the thriving immigrant community in London - it is well documented from previous research that Asian families put a higher premium on education success than indigenous UK families.

A quick comparison of the demographics of Blackpool and Hartlepool shows a higher preponderance of pupils from white working-class families than in London. That is still an issue we have to solve.

As an aside to this story, may I say how refreshing it is to see a think tank using this measure to rank schools rather than just concentrating on exam success.

Mentioning Teach First above reminds me that I’d like to congratulate Russell Hobby, former general secretary of the NAHT headteachers’ union and now chief executive of Teach First. on being selected by Tes as the person who had the most influence on education in 2017.

It is also worth recording that one name missing from the top 10 is the education secretary, Justine Greening - although her schools minister Nick Gibb did make the cut.

When I was education correspondent for the Mirror, we once dubbed then-education secretary John Patten as the Invisible Man on the grounds that he had turned down more invitations to address education conferences than some people have had hot dinners. It could be that Justine Greening is in danger of earning the same epithet for failing to make an impact on the nation’s radar. But, equally, she could be just what we have been waiting for: someone who gets on with the job quietly without wanting to draw attention to herself.

Richard Garner was education editor of The Independent for 12 years, and previously news editor of Tes. He has been writing about education for more than three decades

To read more columns by Richard, view his back catalogue

Want to keep up with the latest education news and opinion? Follow Tes on Twitter and Instagram, and like Tes on Facebook