Local authorities routinely monitor the levels of attainment in their schools, not only to see how they compare with the national average but also to identify schools and departments where the results appear to be anomalous, perhaps indicating the need for extra support or successful methods that should be more widely disseminated.
The reasons for variation are likely to be diverse: a high staff turnover may have meant that there was a lack of continuity in the experience of pupils; a new head may have managed to raise expectations among staff and pupils; a department may have failed to adapt to curricular changes in their particular subject. Whatever the explanation, there are lessons to be learned.
A conversation with a retired member of the directorate provided an insight into some of the variables at work. Instead of adopting a "deficit" model and seeking to find out why certain schools appeared to be under-performing, he was asked to focus on teachers who appeared to be achieving above-average examination results compared with the results in schools with similar intakes of pupils. What was it about their approach to teaching and learning that seemed to make the difference?
He came to the conclusion that there was no single factor which could explain all cases. Some of the very successful teachers were outstanding classroom performers whose lessons were interesting and entertaining: the pupils admired and respected the teacher and, collectively, wanted to do well for him or her. In other cases, good pupil performance could be explained by the teacher focusing narrowly on the requirements of the examination: the aim was clear and the teaching was instrumental and reductionist. Yet other cases could be accounted for by the teacher simply being very well organised: lessons were carefully planned, discipline was good and feedback to pupils and parents was constructive.
However, one teacher in the survey presented a puzzle. She worked on an island school. The evidence showed that her results were significantly better than teachers working in similar schools elsewhere. But her performance in the classroom, as far as my informant could see, was not spectacular. She was a satisfactory teacher but didn't set the heather on fire.
A clue to the mystery was provided by a classroom incident. One of the pupils failed to hand in his homework. He was asked if he had done the work. He replied: "Oh yes, Miss, I've just forgotten my jotter."
"That's fine," replied the teacher. "I'll be passing your house about 7 o'clock this evening so I'll pop in and collect it."
In a small island community there was no escape from the vigilance of the teacher.
My informant had a vision of that pupil rushing from school and getting on with the neglected homework to avoid parental censure and community embarrassment.
This piece of research was never published, partly because it was small- scale and its main function was to inform policy within a particular local authority. There were also sensitive issues to do with confidentiality and the risk of teachers being identified. What the study suggests, however, is that successful teaching comes in many different forms and that not all of the positive influences are exclusive to the school. Parental support, peer-group pressure and community aspiration are all part of the picture.
Walter Humes is research professor of education at the University of the West of Scotland.