Why would a secondary school NOT offer triple science GCSEs?

Not necessarily, and the separate sciences are offered at both foundation and higher level - although the majority of those entered will be taking higher, because most schools only allow/encourage abler students to do triple.
The same can apply with subjects like Latin, which are more often taken by high achievers.

I don't know how they work things statistically - if they know the prior attainment of the cohort taking a particular subject, then that could be used as a guide to the range of attainment that might be expected in the GCSE. Or if the combined chemistry paper is a subset of the questions on the single-subject chemistry paper, they can use that to make sure that similar scores on the overlap correspond to similar overall grades.

The dcs school offers triple science but only to the top 30 kids in the year - I’ve no idea how common that is, but the bulk of them will be doing double.
It depends on timetable.
Often, but not always, the schools that offer triple to the top X number will teach separate sciences in the same curriculum time as the rest of the year studies combined.

Where triple is offered as an option subjects the class(es) taking triple will have the 3 sciences split over the timetable covering combined science plus one option column.

Yes, good point @ThanksItHasPockets.

My nephew's school only offers triple to the top science set and it's in addition to their optional subjects. My son's school offers if to everyone but the additional science is one of their options. I prefer my son's school's way of doing it.

If this applies there is the further benefit that you can enter the separate sciences at varying tiers - so you could do Higher in chemistry and biology but Foundation in physics (and perhaps you did?). This isn't possible in the dual award and you have to take either Higher or Foundation for the full qualfication.

Yes because they have to study an extra third for each science so it’s more challenging. Grade boundaries are also moved every year though so it probably evens out most years

It can be argued that triple science is good if you are weak in one science but good at the others. Back in the day I did all three but was pretty poor at physics. So I scrapped through in physics but got good results in chemistry and biology (and went on to do A Levels in both). Had the double award been around back then my poor physics performance might have reduced my double award so much that I wouldn't get the required 6;6 and wouldn't have been allowed to do A levels.

College A Level teaching is responsive to the intake. If they know they have a significant cohort who have studied dual award then they will plan accordingly. All pupils are going to need some sort of recap of previously taught content, even if they took triple science.

All of the sixth forms in the area we're looking in (south Oxon, Berks, Surrey and North Herts) all offer science A levels to combined science GCSE students. They normally require 6;6.

If triple science is often only offered to high achievers - does that make the exams harder ad the cohort are brighter? As in kids will get a lower score at triple compared to the cohort ad they're all bright than if they did double?!

Dd did double science and then did Biology A level, got a B in her A level.

edited to add, she also moved school for sixth form and in the new school most of the kids had done triple science. But she managed fine in A level.

DDs school does the opposite... they all do separate sciences. Shes in Yr8 and already has separate lessons weekly for all 3. I was quite surprised.

At GCSE they have 3 option slots, which can be any combination of GCSE and BTEch. The school is quite well regarded academically and vocationally... except languages admittedly.

DS's state high school offers triple science to the top 50 or so highest performers in Y9 science tests, but with a lower limit of achieving 75% in these tests. They teach triple science in the same time allowance as double.

"Did their sixth form make allowances for the fact that they did double award though?"
Their 6th form didn't offer science A levels. They went on to college or to the grammar school.

Hardly anywhere does it state schools. My parents asked around a lot as we thought was needed to get into medicine. Definitely isn't. I did double at gcse (a* x2) then biology chemistry for IB

Did their sixth form make allowances for the fact that they did double award though? Help them catch up etc. That's my point - the college A-level teaching works on the assumption that you have triple sciences so any gaps in knowledge will be down to the student to address.

IMO the angst over double/triple award is mostly down to snobbery. A school is not better because it offers triple. Or worse because it also offers vocational subjects.

" the colleges don’t make any particular allowances for those having done double award so any students going on to A-level sciences would struggle." The very many double award kids in our circle who went on to do 3 A levels don't appear to be struggling.

Our schools offer both double and triple. We don’t have school sixth forms and the colleges don’t make any particular allowances for those having done double award so any students going on to A-level sciences would struggle. I suppose it is different in an area where students stay at their school to do A-levels.

A bit random I know but this school isn’t in Hackney by any chance, is it?

I'm so old when I went to school we didn't to all three sciences. So I dropped chemistry. And now I work with chemists everyday. Oh well.

It makes no difference later on, many of us went on to do degrees/postgrad/work in science based fields with ‘only’ double science gcse. My 90s comprehensive didn’t offer all sorts of things I later learnt were available widely elsewhere!

I’m sure some schools

• don’t have the teaching staff to offer triple
• don’t have enough pupils they feel would benefit from triple to run the separate course
• haven’t had pressure from anywhere to do it differently

Definitieoy feel you can ask the school about these issues. Don’t feel you can’t or be fobbed off as being annoying.

Find out too about any implications of choices now for A Level options. You don’t want doors closed that you didn’t realise were being closed.

Grammar school my kids went to only offered double science. Two of my DD's friends are now doctors, I know others did medicine/vet science/dentistry as well as other science courses after A levels. My own kids also did A levels in biology and physics and got top grades so it didn't seem to be an issue.