When Lord Kelvin, one of Scotland's most eminent scientists, said that if you cannot measure a thing then your knowledge of it is of "a meagre and unsatisfactory kind", he was speaking in particular of his own subject. But his words apply equally to education where, as a recent Scottish Council for Research in Education paper on specialist teachers in primary schools points out, much passionate debate relies on "exhortation and assertion" rather than hard facts and figures.
This is particularly pertinent to the dip in attainment when children move from primary to secondary school. Theories on the nature of the ailment abound, as do suggested remedies, but reliable data is scarcer.
The deficiency has been highlighted by HM inspectors in a report on standards in secondary schools over the past five years* (see end note). It is also a concern to schools, particularly those that have demonstrated a commitment to science for younger pupils, which, as the inspectors point out, is often accorded "considerably lower status" than other courses.
"If you talk about the dip in S1 and S2," says Richard Staite, headteacher at Beeslack High school in Penicuik, Midlothian, "you've got to be very sure of the statistical base you're using to measure it. And of course we're not. If you compare S2 and S4, for example, the pupils must be making exponential progress."
This is not to deny that the problem exists: Beeslack High would not have developed a highly-regarded project for improving attainment in the lower school if the staff thought it unnecessary. Rather, it is drawing attention to one area where national guidance and resources could bring greater clarity, focus and consistency to the work of teachers.
Initially, Mr Staite admits, his science teachers had little knowledge of what constituted science in primary schools. So the scheduled time they spent at Beeslack High's feeder primaries each week - half a day for each teacher - was a process of discovery for them, a "gradual development of understandings I through observation of pupils at work and formal time for teacher discussion".
Improved understanding was accompanied by the teachers' growing confidence both in each another and in the approach they were mapping out together for the children. This allowed them to move through several stages of increasing refinement and definition and eventually to produce detailed guidance on what to teach and when and how to teach it. All this is now contained in bulging folders of learning outcomes, methodologies, assessments and how-to sheets used by teachers in both schools.
The consequent gains in contnuity and coherence from Primary 6 to Secondary 2 will go a long way to addressing the concerns and recommendations of HM inspectors, in particular that secondary schools should be aware of children's experience and attainment in primary schools and should no longer take a fresh start approach to teaching science.
Beeslack High's innovative approach to primary-secondary liaison is a very powerful model, says Mr Staite, which could be adopted elsewhere. However, the prospect of the very productive, but prolonged and intensive efforts of these teachers being duplicated 400 times in clusters around the country is not one that can be viewed with equanimity.
"Science teachers need to be careful how much time and energy they spend developing materials," says Ian Wilson, Beeslack High's principal teacher of chemistry. "There's no point in everybody reinventing the wheel."
There is one further point. On paper Beeslack High has four associated primaries, but in practice its pupils come from no fewer than 22. Thirty per cent of the new intake each year is from primary schools that have not taken part in the cluster project. And while the high numbers may be unusual, the pattern is repeated across the country. So, although there would undoubtedly be gains for the majority of children if all schools worked more closely in clusters, this cannot be the whole answer. That very co-operation would create a minority who could, relatively speaking, be worse off than before.
"We are quite concerned about how to deal with children from the 18 schools who did not take part in the project," says Lesley Johnson, Beeslack High's assistant principal teacher of chemistry.
Mr Wilson regards the revised 5-14 environmental studies guidelines as "something of a missed opportunity" and mentions with approval the much more detailed guidance on teaching and assessment provided for Higher Still.
Ms Johnson goes further: "I don't want to be too negative but we're told nowadays that learning outcomes are the key. You introduce them at the beginning of a lesson, consolidate them at the end, all your questioning is aimed at them and students know that assessments will be based on them. So why couldn't they have taken that extra step in the guidelines and produced learning outcomes?
"I do understand - and our colleagues in the primaries have shared with us - the worry about it all becoming too prescriptive. But there's plenty of scope to diversify methodology while meeting the same learning outcomes."
* Standards and Quality in Secondary Schools 1995-2000: The Sciences. Despite many positive findings, the inspectors found that 65 per cent of the 325 science departments assessed had "significant weaknesses" in addressing pupils' needs in S1S2