The number of children being expelled from school in England is rising, after falling for years.
There were about 1,000 more permanent exclusions in the year 2015-16 (6,685 exclusions in all) than there were the year before, according to government statistics. That's out of a total of the roughly 8 million children attending state schools in England. It works out as eight in every 10,000 primary and secondary school pupils, up from seven in every 10,000 the previous year.
It's something the government says it's going to look at, in a review led by former children's minister Edward Timpson.
But what do we already know about who gets excluded?
Certain groups of children, and children in certain parts of the country, are much more likely than average to be expelled from school.
Special educational needs
Almost half of all exclusions - either permanent or for a fixed period of time - are of pupils with identified special educational needs.
Children with special educational needs are seven times more likely than the average to be permanently excluded, although this proportion has actually slightly fallen as the total number of exclusions has risen.
Special educational needs cover a wide range of difficulties and disabilities, which makes learning harder for these children than for other pupils of a similar age.
By far the most common reason given for permanently expelling a child is "persistent disruptive behaviour". Other less common reasons include physical and verbal abuse, bullying, racist or sexually inappropriate behaviour and drug and alcohol use.
This isn't the whole story, though.
The official statistics only capture formal exclusions. But there are concerns that some children are being "managed out" of schools in less formal ways.
Exclusions in numbers
- More than a quarter of permanent exclusions were pupils aged 14 - those just about to start their GCSE courses
- Boys were more than three times as likely as girls to be permanently excluded
- Pupils claiming free school meals - available to households on lower incomes - were about four times as likely to be excluded
- Pupils receiving support for special educational needs were the most likely to be excluded (seven times as often as those without special educational needs)
- Black Caribbean pupils were over three times more likely to be permanently excluded than the average
- Children in the West Midlands are twice as likely to be excluded (12 in every 10,000) as children in the South East of England (six in every 10,000)
Source: Department for Education
A report by centre-left think tank IPPR, published in October, found the total number of children being taught in "alternative provision" for excluded children is far higher than the total number of reported exclusions.
When children are excluded from mainstream or special schools they often end up in a pupil referral unit or an independent or non-registered school.
Part of the gap identified by the IPPR is thought to be down to children who were informally excluded and so don't appear in the exclusion statistics, but do appear in the census of children in alternative provision.
Another part of the explanation may be children staying in alternative provision for more than a year - so in subsequent years they appear in the alternative provision data but not in that year's tally of exclusions.
But pupil referral units were not designed to be permanent settings for children to complete their compulsory education. They were designed to refer them on to another mainstream or a special school.
Kiran Gill, one of the authors of the IPPR report and founder of charity The Difference, says: "Increasing numbers of children are being referred close to their exams and end up doing their exams in pupil referral units."
She says only 1% of GCSE candidates in pupil referral units leave with the five good GCSEs they would need to continue with their education (A*-C under the old system or grades 4-9 under incoming GCSE reforms).
Last January, more than two-thirds of all pupils in alternative provision were in Years 10 and 11 - their GCSE years.
School inspectorate Ofsted has raised concerns that schools are removing children from their rolls as they approach GCSE as a way of "gaming the system" in performance tables.
There also appears to be a group of children who are being repeatedly, informally sent home from school due to difficult behaviour without ever being permanently, formally excluded, according to Catriona Moore, an education policy expert at the National Autistic Society.
These children miss out on large parts of their schooling without showing up in the exclusions statistics, she says.
Of a survey of 2,573 parents conducted by the charity, one in four said their child had been "informally" excluded at least once in the last year.
Malcolm Trobe, of the Association of School and College Leaders (ASCL), says schools also have to consider the other children in a classroom.
"If you have a child whose behaviour is extremely disruptive and it's impacting the education of 28 other children in the class, you may have to take some serious action," he says.
He adds that funding pressures have meant schools are less able to access external support like counselling, behavioural management and mental health services for young people and in some cases, "the only way to access this external support for a child is to have them excluded".
Launching the government's external review of school exclusions, Education Secretary Damian Hinds said: "Children only get one chance at their education and they deserve the best. But for too many children - and often those who are most vulnerable - there are inconsistencies when it comes to their experiences of school and too many parents are left worried and concerned.
"That's not good enough which is why we are going to improve our understanding of these important issues and tackle them head on."