Schools all over the world are under pressure to improve, and inspection is often seen as a way of achieving higher standards. But if it is to have a long-term positive effect, schools need two kinds of evaluation: rigorous external assessment which identifies strengths and weaknesses, and advice from understanding professionals ("critical friends") who appreciate the school's situation and can devise workable strategies for improving it. A combination of pressure and support is essential: merely identifying weaknesses is not enough.
Some governments are also pinning their faith on various forms of performance indicator (such as examination results) as a way of identifying successful and unsuccessful schools. These can indeed be helpful, but the best way of using them is still unclear. Gathering large amounts of data and subjecting it to complex analysis is time-consuming and expensive, and should not be engaged in simply because the technical expertise is there.
These are the main conclusions of research which I carried out last year for the Organisation for Economic Co-operation and Development - in collaboration with Donald Hirsch, a former official with the organisation, now an independent consultant. Together we examined how seven very different countries (England, France, Germany, New Zealand, Spain, Sweden and the United States) evaluate the performance of their schools. The result is Schools Under Scrutiny; Strategies for the Evaluation of School Performance, a report to be published next week by the OECD's Centre for Educational Research and Innovation.
Under the pressures of global competition, many OECD countries have become anxious about the performance of their education systems. Virtually every education system in our study has recently undergone root-and-branch reform, and their schools now face testing times: taking more responsibility for their pupils' performance, being subjected to increased public scrutiny and - in some countries - being thrust into a competitive environment.
In this climate of upheaval and strenuous self-improvement, life may be harder for schools, but they have also become much more important players. In most countries, the aim of putting pressure on the schools is twofold - to improve the quality of education, and to make the institutions more accountable to society.
There are really only two ways of evaluating schools: inspection or review (that is, actually visiting schools) and the use of performance indicators. Different countries use different combinations of the two methods.
Four of the nations in our study have a national inspectorate, three of which are operating through brand new systems. New Zealand's Education Review Office performs a similar task to that of the Office for Standards in Education in England and Wales. Neither of these new bodies is responsible for advising or supporting schools - although the national frameworks and guidelines used by schools in preparing for an inspection are widely seen as helpful.
In Spain, the inspection system has also been overhauled. The new-style inspectors are responsible for checking on the progress of the country's recent education reforms, and encouraging schools to adopt them. Each inspector has a caseload of schools which he or she knows well. During formal inspections, this inspector becomes one of a team of three - the other two being external assessors, unfamiliar with the school.
The French, too, have two types of inspectors, who have recently been encouraged to work together. Local inspectors know their schools well, but normally focus on the work of individual teachers rather than of schools.
The high-status Inspecteurs Generale, who inspect schools for the Ministry of Education in Paris, have recently become very interested in schools as units. Their reports focus on the strengths and weaknesses of individual schools - although such inspections are often part of an overall look at a particular sector.
The Swedes do not have a national inspectorate. In their reformed system, the local municipalities are responsible for assessing schools. Inspections, which are infrequent, are seen primarily as an aid to self-improvement - although Swedish politicians are becoming increasingly interested in accountability.
There is no tradition of nation-wide inspection in the United States, and until recently most evaluations were of entire school districts, not individual schools. A handful of states (including California and New York State) are currently experimenting with various forms of school review.
The key performance indicator in all countries remains the level of examination passes or test scores of the students - in spite of the now well-known but still intractable problem of devising fair "value-added" scores. The US has depended for decades on standardised tests unrelated to the curriculum, but widespread dissatisfaction has led to the development in some states of "authentic assessment" aimed at giving a more accurate idea of what students have learnt. Some school districts in the US now publish data of this kind - sometimes with the objective of comparing schools.
The British government publishes performance tables for secondary schools in England and Wales, with the express intention of comparing schools. In France, three performance indicators based on the baccalaureat results are published every summer for every lycee (upper secondary school), but competition between schools is not officially encouraged. The French Ministry of Education also furnishes schools with a battery of indicators which they can adapt for themselves and use to reflect on their performance. In New Zealand, too, self-review is encouraged.
It is clear that both inspection and performance indicators have something to offer most countries, but neither is a magic wand for school improvement. In particular, accountability and raised standards, so often linked in government thinking, are not necessarily related. Accountability may be very desirable, but simply making schools "accountable" is unlikely to improve performance.
Above all, school evaluation is not an end in itself, but the first step in the long process of school improvement.
This is most likely to occur when the expertise and professionalism of teachers is used as a starting point.
Thorough and focused programmes of staff development, which enable teachers to change and grow, are indispensable elements of the process. The aim must be to encourage a climate of self-review, so that more schools become real "learning organisations", capable of continuous improvement. This is the most important contribution a good evaluation system can make.
Schools Under Scrutiny: Strategies for the Evaluation of School Performance is available from HMSO bookshops, or from OECD Publications, 2 rue Andre-Pascal, 75775 Paris Cedex 16, France, price Pounds 25. The report is the second in a series of short, self-contained policy-orientated OECDCERI research studies entitled What Works in Innovation. The first one, School: A Matter of Choice, which came out in 1994, looked at policies on parental choice of school in six OECD countries. The third report in this series, due to be published in 1996, will focus on educational and career guidance in Austria, Canada, Finland, Italy, Japan, Mexico and Scotland.