Even allowing for the reluctance of teachers to leave their work behind them, the incident - and others like it - says something not merely about the extraordinary impact of the Panorama programme in June, but suggests that this time it touched a troublesome perennial.
Don't let's delude ourselves that the issue of class teaching is new. It has dogged teachers down the years.
And despite the composed and thoughtful way in which the matter has been discussed on television, and subsequent balanced debate in The TES, I believe we are still missing or evading the critical point. We shall only resolve the issue and, incidentally, avoid adopting wholesale a pedagogical approach limited in important respects, by looking in detail at the true implications of whole-class teaching.
Well-aired matters aside - the difficulty of drawing general conclusions from radically different cultures and limited samples, the significance of homework religiously completed, the possibility that the mathematics involved was particularly amenable to transmissional teaching approaches, and so on - there is no question that whole-class teaching, properly executed, is a powerful and essential educational technique. It conveys important information memorably and economically, with more immediacy for young children than the printed word; it can enthral and captivate, encourage intellectual curiosity, promote participation and interaction, provide for instant assessment and feedback, and can generate pace and urgency.
But that is only half the story, and therein is the dilemma. We have to consider other implications that may not have been sufficiently explored in even the most authoritative literature.
The fact is that a whole-class lesson, no matter how efficiently it is delivered, no matter how tightly organised the content, will leave a significant proportion of children misunderstanding, or failing to grasp, possibly vital elements, which others will have assimilated, often well before the session ends. That was partly admitted in relation to the Taiwan lesson shown in the Panorama programme. The more able children simply waited for the others to catch up. Some never quite managed it; their friends apparently helped them "to understand in the breaks". Really? Not even in Taiwan, I suspect.
a nd what about the more able groups - not gifted, simply the 20 to 30 per cent capable of managing the lesson content. We could, working to the chief inspector's projections, assume that in a 40-minute lesson, half of which was devoted to the teaching element, the more able third of children may have grasped what was being taught in 12 minutes. That means eight minutes of fallow waiting, while others demonstrate on the board a general attempt to come to terms with the subject matter. Nothing to be greatly concerned about, it might be argued - eight minutes here or there. But in sequences of lessons over long periods this could amount to a serious matter of accumulated hours.
Going further, one might also assume that when it came to the practical work of the lesson, the more able would either engage in the common task, or be given more challenging material. Whatever the option, and whatever the progress being made by certain children, whole-class teaching would require them to come back at the beginning of each new session to a common starting point.
The second difficulty we are faced with is that so large an emphasis on whole-class teaching is likely to make certain important elements of subjects more, rather than less difficult for the children to learn, as a single glance at the number attainment target will exemplify.
Large parts of the national curriculum subjects are simply too complicated to explain orally to a mixed-ability class where, as the Cockcroft report pointed out, it is possible to have a cognitive spread of as much as seven years.
Many may baulk at the notion that significant elements of the national curriculum will only make sense when children can be actively engaged (which does not necessarily mean an activity-based approach; active learning may be about reflection, analysis, deduction). But if children are to understand certain vital concepts and master certain essential skills they have to try things out in a practical way, to learn by trial and error and by reflection on their mistakes.
It is this critical part of children's learning, requiring the most ordered learning and meticulous organisation by teachers, that leads to coarse generalisations about discovery methods. Of course, teachers get it wrong; certainly such teaching may be beyond achievement in the complex context of the upper part of key stage 2; understandably it would appear safer to put all our eggs in the whole-class teaching basket. But in the end it just won't work. We might as well pretend that surgeons can learn their trade in the lecture theatre, with the first faltering incisions tackled in the time that's left over; that pilots can learn to fly from illustrated talks, and take the tiller in turbulent seas as an after-thought; that electricians can learn more from the blackboard.
I suspect we are all grasping at whole-class teaching as a solution to a perennial problem, too large, because of the demands of the national curriculum, to ignore any longer. But the answer is not in radically increased whole-class teaching, powerful and essential as that is, but in providing opportunities for extended interaction - not less than 15 minutes at a time - between teachers and manageable groups of children. I wonder whether that is not an important element of the Barking experiment. Certainly the class of 14 we observed on television would be regarded by primary teachers as a very manageable teaching group so far as size was concerned.
I venture to suggest that Professor David Reynolds of Newcastle University got it almost right when he talked about "high quality whole-class interactive teaching". It is essential we persevere with that, refining as we go, getting the time allocations right, identifying the subject elements that can be most effectively taught in that way and getting the cognitive challenge right for the third of the class at opposite ends of the ability range.
But the real answer, I believe, may lie in consistent, extended, high quality teacher-group interaction. Whether we will ever face the implications of that is another matter.