The test is usually taken early in the last year of primary school but parents often start pondering over whether to do it and how to prepare much earlier.
Here's our guide, with everything you need to know to maximise your child's chances of success, whilst minimising all the stress.
What sort of schools have 11+ testing?
Selective state schools, commonly known as grammars, choose their pupils at least in part based on academic ability, whereas comprehensives have only non-ability based criteria for allocating places, such as distance from the school to a prospective pupil's home or affiliation to a particular religion.
Children who are hoping to attend private secondaries might also face an 11+ test, set either by an individual school or a consortium of schools. Whilst grammars are nowhere near as common as they were fifty or sixty years ago, over 200 still remain, concentrated in a few areas of England and in Northern Ireland where the 11+ is also known as the Transfer Test. There are no remaining selective state grammars in Scotland and Wales.
A few secondaries retain the word grammar in their name for historical reasons but are actually now comprehensives or private schools.
So can anyone take the 11+?
Many grammars have catchment areas and pupils must live within the area by a set date to be eligible to take the exams and potentially gain a place. A few schools, sometimes known as 'super-selectives', have no catchment area at all and anyone living anywhere can apply - selection is solely down to who does best in the exams.
Some grammars are faith schools too and for these, proof of observance of a particular religion might be important if the school is oversubscribed (which being a grammar, it inevitably will be).
Do all children sit the same test nationally and what do they cover?
Tests are set locally, either by the school, a 'consortium' of schools or at county level.
What's tested therefore varies. There is usually a mix of some, or all of, verbal reasoning, non-verbal reasoning, maths and English.
If you have a specific school in mind, it's very wise to check which subjects are included in their tests. Specialist website 11+ website and discussion forum, Elevenplusexams.co.uk is a mine of information on this, and indeed everything 11+ related.
Would my child be interviewed as well as sitting exams?
State schools of any type are no longer allowed to interview prospective pupils or their parents. It all comes down to performance in the tests. Children trying for selective private schools might well be interviewed though.
Should my son or daughter sit the 11+ exam?
If they're obviously highly able or conversely a grammar school education is clearly not right for them, it's a relatively easy decision but for parents with children anywhere in between, whether to do the 11+ can be less clear-cut.
Your first port of call should be their teacher or headteacher. In areas where the 11+ is very common, you should be able to receive guidance on all this from them. Parents' evenings late in year 4 or early in year 5 are a good time to start getting an indication of your son or daughter's suitability.
In some places where only a small proportion of children take the 11+, schools will not provide much of a view on this, due to lack of experience or an unwillingness to get involved. In this case, it might be worth finding a well-thought of local tutor (see below) and getting them to assess your child.
Check the tutor knows the schools you're considering well and has prepared children for them in the past. You will have to pay for the assessment, which might take one or two hour-long sessions.
My child's top of their class. They'll be a dead cert pass right?
Be careful of looking at their chances based on where they are at in their class or which ability table they sit at - some classes or year groups will be especially bright and some not, so a 'top table'/ top set child in one class or school, might actually be more average in another.
Instead, look at their National Curriculum levels - most teachers will be happy to provide these at parents' evenings. These will give you a better idea of how your son or daughter is doing compared to average for their age.
We haven't anything to lose by letting our son have a go though so why shouldn't we just put him in for it?
On the one hand, you risk him feeling disappointed or damaging his confidence if he doesn't 'pass', on the other, you might decide that it's worth a try even if success is unlikely - you never know, he might have a good day.
Lorrae Jaderberg of Jaderberg Krais, an education consultancy, warns against a 'taking a punt' approach, advising parents to think carefully about signing a child who is not likely to pass up for the 11+.
"This is a challenging experience for the most suitable and prepared children, so putting them through it if they have no chance of being successful would be irresponsible, as they may suffer anxiety and trauma unnecessarily."
Fellow Parentdish writer Glynis Kozma is a former teacher and established tutor. She says: "Be realistic - if your child is performing at an 'average ' level then it's unlikely they will cope with grammar school even if they do pass.
"It may be possible to tutor them through the 11+, but if they can't hold their own thereafter or are the lower end of the grammar school, it may not be the best place for them."
Indeed although some parents assume that being in a 'brighter than you' group of peers will be a positive influence, research shows that pupils who struggle to keep up often fair worse than if they'd been in a more academically mixed school, due to damaged confidence.
OK, we've made the decision to go for it. What now?
It's wise to do some preparation for the tests. Sending a child into the exam room who has never encountered the kind of questions involved will do them no favours when the fact is most other candidates will have had some prepping these days.
How much to do and when to start are difficult questions to answer though. What's needed will depend on where your child is at academically, how competitive it is to get a place at your target school(s) and if they will do any swotting up for the 11+ at their primary school.
In some areas, a couple of months of an hour or two a week will suffice, in others, where grammars are massively over-subscribed, you might need to start considerably earlier, and do more, to give your child a fighting chance.
Lorrae suggests looking to get stuck into some exam prep from around 15 months before the tests, recommending a slow and steady approach over leaving it all to the last minute, which will be more stressful.
Lizzy, a mother of two in a very competitive 11+ area, took the long approach with her daughters: "Friends outside our region thought we were bonkers to begin the girls on workbooks and the path to the exams so early - we started in year 4 - but we preferred to do a little for a long time rather than getting to a few months before the tests and having to cram.
"I wish it wasn't this way at all but the reality of where we live is that if the girls were to stand a chance, we had to do the legwork - otherwise it would not be a level playing field when all the others were getting tutored."
Emma-Jane, whose daughter is now at a Kent grammar, meanwhile found that a couple of practice papers a week for two or three months was plenty. "I know some who got in did more but we didn't think it was necessary. She just needed to have an idea about exam technique and to not get freaked out by the whole situation."
Is a tutor essential?
Some parents find self-tutoring their kids works out fine - with the bonus being that it's cheaper - but hired help is increasingly common for the 11+. There are quite a lot of considerations here:
Reasons to tutor
* A good tutor will know the type of exams at local schools and their questions inside out.
* They should be able to give you perspective on your child's chances (albeit they can't tell you for sure whether they will get in or not!) and advice about which schools to try for.
* Some children are more likely to want to complete work for their tutor than their parents, making it less of a battle.
* If your child goes to the tutor's home or office, there might well be fewer distractions around when it comes to getting down to work - no TV, computer games or younger siblings running about.
Reasons to skip the tutor
* You'll have to commit to a specific time slot each week (although this could be a positive as it will give you a timetable and structure to ensure homework gets done).
*The expense! Some London tutors charge as much as £50 an hour. £25 to £30 is pretty normal elsewhere.
*You might not have the same knowledge of the tests and process as a tutor (although you know your child and what makes them tick better than anyone).
Note too that some areas and schools are looking at 'tutor proofing' tests. The idea is that those children from families who can't afford tutoring aren't disadvantaged and the tests will assess ability rather than how coached a child has been.
I do want a tutor, how can I find a good one?
Glynis advises parents seek one through recommendation - perhaps asking around amongst any families you know with children at the schools you're hoping to get into (although other parents can be surprisingly cagey about passing on details of their tutor!) If that draws a blank try going via a reputable agency.
Make your own enquiries about the tutor including seeking references from other parents. The tutor should have experience with the 11+ (not just of teaching in a school) and ideally of preparing children for the specific schools you're looking at sending your child to.
Can they talk knowledgably about the tests for that school? Do they know which subjects are covered? Ask them about their success rates - how many of their pupils got into their first choice school last year? Be wary of anyone who seems to have a lot of availability - any decent tutor will be fairly booked up!
Remember that tutoring is unregulated and anyone can set themselves up as one. All tutors should have a DBS check.
What about group tuition?
11+ tuition groups operate in most area with grammar schools, run either by individual tutors or agencies/ tutoring companies. It will be cheaper than individual tuition and can bring a sociable element to preparations but on the downside, your child won't get the same one-on-one attention.
Ask about class sizes, check how individualised the teaching is, what the tutor's qualifications are and what scope there will be for you to get feedback and guidance about how your child's doing.
How can I help them prepare without a tutor then?
It's perfectly possible to take a DIY approach to the 11+ and many parents do so successfully, although sometimes the parent-child dynamic can make things challenging!
Again, the Eleven Plus Exams website has lots of information and resources plus recommendations for workbooks and other useful materials.
It's really hard to get my daughter to sit down and get on with it. Most of her friends aren't doing the 11+. How can I motivate her?
It's a wise move to get children to 'buy into' the idea of going to your target school - it's much easier to get them motivated if they love the idea of a particular school.
Take them to the open day and hope they'll want to go there so much that they'll be willing to put a little work in.
Be careful though not to talk the place up so much that going there becomes the be all and end all...just in case she doesn't get a place!
How can I keep my child calm through the exam?
The 11+ can be horribly stressful. Lorrae's tips for keeping children relaxed include trying not to talk about it all too much, creating a schedule and keeping to it so there doesn't need to be additional discussion about what to do when, and giving lots of positive feedback about how well they're working and doing their best.
She adds: "Listen to their concerns and provide reassurance that they are doing really well. Do not express your own worries about all this in front of your child at this stage."
Immediately before the test, Lorrae suggests "total relaxation - early nights, hot baths, watching TV and putting their feet up. Let them switch off their brain and rest!"
Last-minute cramming is unlikely to help and might just make things worse if it panics your child or tires them out.
Should I offer them a reward for passing?
Lots of parents promise their child a reward around the time of the exams. If you do this, ensure that it's for their efforts not for results per se, as the thought of not getting into the school AND not getting their reward might well just add to their stress!
How can I keep myself calm?!
If you feel your blood pressure hiking up as the exams loom, you're not alone. This can be a tough time for parents.
All the usual relaxation techniques, from yoga, to going for a run or settling down with a nice glass of wine and reading a good book are what the anti-11+ stress doctor ordered.
On a practical level, mother of two, Farida, an 11+ veteran whose son and daughter have both taken selective school exams reckons being organised is crucial. "Make sure you have all the exam dates on a piece of paper and stick it up somewhere. Keep all the paperwork carefully – the schools send endless badges and parking badges and instructions. If you're in flap about it, your child will get nervous.
"Make sure you drive to the school before the big day (maybe on an open day or the same day the week before) so you know the route. Don't get stressed when you see a sea of cars and parents with their little prodigies – just be cool and talk to your child."
I think we're going to go crazy before results day! Help!
Don't dwell - once the tests are over, they're over and there's nothing you can do to change the results.
It's tempting to grill your child for details of their answers or ask how difficult or easy they found it all but this is notoriously unreliable as an indicator of how they've done.
Some children who come out saying it was a doddle, may not have read the questions properly or understood their complexities. Others who didn't finish all the paper, might be unaware that no-one else did either.
Don't torture yourselves and definitely don't listen to the mum at the school gate who is bragging about how her kid found it all easy-peasy...
Also on HuffPost: