By Gary Eason
Education editor, BBC News website
A-level biology students have been shocked to find that candidates doing an exam experiment in some schools were given the outcomes in advance.
The test involved details related to leaf stoma
While most were struggling to count tiny holes in leaves under a microscope, some had a "crib sheet".
Exam board OCR has apologised for any distress caused. The QCA watchdog has demanded an explanation.
Some head teachers are saying the exam should be scrapped and either re-run or replaced by students' predicted grades.
Posts by sixth formers in an online forum also suggest some knew in advance what the subject was likely to be.
The exam, taken on Tuesday afternoon, was OCR's Unifying Concepts in Biology / Experimental Skills 2 (Practical).
It was taken by some 7,500 students in 317 centres.
Question 2, worth a fifth of the marks, involved microscopic examination of three leaf samples soaked in different solutions, to calculate the percentage of tiny holes called stomata that were open in each.
Candidates then had to explain the differences they had observed - but some were short of time having struggled to obtain the data.
OCR said in a statement that it was aware some schools and colleges had experienced problems with the A2 biology practical and it had been working closely with them to alleviate those problems.
It said 24 schools and colleges had found it difficult to generate the expected results and another 19 had been unable to obtain the species of plant required for the experiment.
"Where this was the case OCR supplied a sample set of data and appropriate material so that candidates could tackle the relevant questions.
"OCR is putting in place procedures in the marking process to allow for difficulties experienced by centres.
"OCR apologises for any distress caused to students who were unable to fulfil the practical in the desired manner and can assure them that no candidate will be disadvantaged as a result of this."
Advice in advance
The headmaster of independent Brighton College, Richard Cairns, said: "Sixth formers up and down the country have been disadvantaged by an examination that was flawed in its inception - and which the board knew to be flawed."
He also called on the government to ensure more effective external monitoring of practicals.
Mr Cairns added: "It is very clear from some of the comments made in The Student Room that some students seemed to know rather more about the examination to come than one might have anticipated."
The Student Room is an online student community with a forum used by sixth formers.
Comments posted before the exam included the predictions:
The advice on stomata was written by a student at Derby Grammar School, an independent boys' school.
- "I'm doing the same practical. It's on photosynthesis and plants etc, it's got nothing to do with human bits from what I've heard."
- "We've done a couple of practical mocks recently with a couple of recurring themes, those themes being hydrogen acceptors and photosynthesis in part 1 and then stomata in part 2."
- Then, in response to a question about this: "It was all about opening and closing of the stoma so stuff to revise..." [advice follows] "If I had any money in my bank account right now I'd put it on stoma coming up as the question 2 slide!"
Headmaster Roger Waller dismissed the idea that students had known in advance what to expect.
As a scientist himself - he has taught chemistry for 32 years - he tells boys every year the three things they need to swot up on for a practical.
"That's the unfortunate thing these days about practicals: a lot of schools don't have the equipment so they put on simple ones and you can almost guess what they are going to be," he told the BBC News website.
He said his students had managed to do the experiment and get results, albeit using a different type of leaf because of problems identified in advance by the science staff.
But he was "appalled" that OCR had sent the data to some schools.
"I think it's impossible for OCR now to standardise the marking," he said.
"I personally think they should withdraw the practical examination results and ask all schools to give the predicted mark out of 30," he added. All schools would have this, based upon mock exams.
"Or simply they will have, or should have, reserve practicals and there's no reason why after half-term or towards the end of June they could ask all schools to resit the practical."
He was appalled if OCR thought it could use this exam towards the A-level grades of students who were for example hoping to go on to study medicine at university.
Mr Waller was backed by the general secretary of the Association of School and College Leaders, John Dunford.
he said the blunder would have been "very distressing" for students and their teachers.
"It is quite deplorable."
In the students' forum, comments after the exam complained about the difficulty of the procedure.
People also said:
- "We got given the results for X, Y and Z because apparently there had been many complaints about how hard it was to actually get it to work!"
- "We got given the results, stomata count and everything. Our teacher said there was a problem with it so we had to use the answers the board gave us."
- "I think it's unfair that some schools had to actually do the experiment while others didn't (i.e. my college)."
- "I think it's very unfair that some schools were given the sample results. My teacher said he emailed OCR last week and they said it is no longer allowed for students to be given sample results."
- "It sucks! Seems quite a few of u got given the answers to part 2!"
- "Oh, I feel so sorry for everyone that had to do the experiment in part 2. My teachers couldn't get the experiment to work, so the exam board sent us a 'new' question 2 with all the answers and a nice little insert with the pictures of the stomata on."
- "Luckily our teacher gave us the mark scheme results and I copied the results and adapted them a bit."
- "What the hell? I don't know about anyone else, but that sounds like cheating."
- "We basically entrust our futures to the exam boards, so when they do something like this it's rather worrying."
A spokesman for OCR added: "We are investigating the posts on The Student Room."