This means that an inspector is making this judgment for each lesson, and to do so must be judging the “capabilities” of the pupils in the classroom, as well as their standard of achievement, in each individual lesson observed - typically in a 20-minute visit. As a teacher I find it takes me quite a long exposure to a class to feel I have got the measure of what they are capable of achieving. My teaching would be much more effective if I could do so accurately in 20 minutes. Could you reveal how it is done?

A. I have to begin by saying that I hope most “observations” are typically longer than 20 minutes and that not all lessons have to be “scored” for achievement in relation to capability.

However what you are contending is that inspectors would need far greater knowledge than they can possibly acquire of the children observed, before making the kind of fine judgments that establish, for example, that a class is achieving satisfactorily in relation to ability while falling below national norms.I think few people would ever be confident that they are managing exact judgments about children’s capabilities.

We all have first-hand experience, for example, of children who repeatedly exceed our expectations of them. But OFSTED does not require inspectors to make speculative judgments about possible potential. Inspectors are expected to apply certain evidence and criteria to determine whether classes of children are achieving as much as seems possible and appropriate for them.

It would be all too easy to reach a state where we are inhibited from making any judgments at all about children’s achievement because of the apparent enormity of the task or for fear of getting it wrong. Teachers have to make such judgments all the time, often when children are relatively new to them. Similarly, informed “outsiders” to a class, even with limited time, can often be secure about the judgments they make. Let me quote an actual case: children required to “colour code” and add up in work books groups of coins of different value, never totalling more than 30p who, when invited to work out the value of a large handful of mixed coins exceeding Pounds 2, did so quickly and accurately, without recourse to written calculations. It was only too evident that these children were achieving short of their capability because the tasks on which they were engaged constrained them from doing more. Observers might confidently make similar judgments about articulate, “well read” children producing banal writing, exuberant children performing apathetically in PE, or otherwise competent, children making indifferent music.

Alternatively, inspectors may feel secure in judging that children who cannot make maps and plans using pictures and symbols, but can describe their journey from home to school; who cannot write to organise and communicate ideas but can manage narrative; who can count in steps of different sizes, but cannot yet recognise sequences, are failing to achieve national standards, but are achieving at levels compatible with their ability.But what about the commoner, less clear-cut cases? How can an inspector new to a class be sure about judgments or capabilities in subjects such as geography or technology where national norms themselves are difficult to define.

The honest answer is, of course, that in hard cases such as these, inspectors can feel far from certain; hence the caution whith which they are obliged to make judgments. But it is important to remember that they do not come uninformed to the task. Their generally wide experience of children’s learning cannot be discounted. They have, in common with most teachers, considerable knowledge of learning. The work that teachers provide for children has always been partly based on intuition about their capability, derived from knowledge of their previous experience and achievement.

That kind of experience, shared by inspectors, allied to the objective guidance provided by the national curriculum, should help them to make, at the very least, broadly valid judgments in these more difficult cases. This, of course, is not all. Inspectors come to OFSTED inspections equipped with a formidable body of knowledge about the children they observe, based on considerable pre-inspection evidence and extensive school documentation. These include:n “The Head Teachers’ Form” and the “Pre-Inspection Context and School Indicator” report.These enable inspectors to summarise the context in which the school works and the background of pupils with reference to the area served by the school, the socio-economic background of pupils, sometimes the levels of achievement on entry, and special needs; * evidence of children’s achievement and capability from national curriculum and other tests, and from the whole range of school assessment; * profiles of children’s work, designed to provide a record of development and achievement; * representative samples of children’s work selected by teachers.

This evidence is supplemented by interviews with the children; evidence from annual reports to parents about individual children’s progress; access to teachers’ lesson planning, together with provision for differentiation; the children’s everyday work, in conjunction with their responses in lessons; sampling of children’s literacy and numeracy; general discussions with children about work and interests; discussions with curriculum co-ordinators about expectations and achievements and discussions with class teachers.

Inspectors probably feel these factors help to ensure that the broad judgments they are required to make are generally reliable; having said that, I am sure that many inspectors and certainly I, personally, find judgment about achievement the most challenging element in the whole complex business of inspection.

Bill Laar is a registered inspector.Write to him co The TES, Admiral House, 66-68 East Smithfield, London E1 9XY.