David Sang is working on survival guides.

Last month’s A-level results showed a further drop in the numbers graduating from our sixth forms with science qualifications. We have seen two decades of more or less steady decline in the popularity of science subjects among 16 to 19-year-olds, despite the fact that the numbers with a suitable background for going on to study the sciences at A-level has greatly increased.

One reason for this failure may lie in the nature of science teaching at secondary level. Science teachers are often expected to teach all aspects of the subject - physics, chemistry, biology and earth science - particularly to pupils in the early secondary years, while they may be graduates in only one of these areas with limited backgrounds in other areas. The Institute of Physics has estimated that there are, roughly, as many physics graduates in teaching as there are secondary schools. Since there are many schools that rejoice in more than one physicist, it follows that many pupils reach the age of 16 without having been taught by a physicist. The same is true for chemistry, although less so for biology.

At the same time, a culture has developed where it may be thought of as wrong even to mention the different strands of science - the subject is presented as a seamless whole with a single methodology - whereas in reality there are many different sciences, each with its own methods, ideas and subject matter. The work of an astronomer, for example, is necessarily very different from that of a molecular biologist.

From a management point of view, it is convenient to treat all members of the science department as equally competent across all of the sciences. It makes for easy timetabling and teacher shortages in one area can be compensated for by recruitment in another. While a biologist can make a good job of teaching physics and vice versa, for most of us, this isn’t easy. My own experience has been as a physicist; when new to teaching, I was relatively confident with the trolleys, glass blocks and radioactive sources, but I was never quite sure what would happen when I dropped sodium on to water, or how to respond to a child with brown eyes whose parents’ eyes were blue.

There’s much more to teaching science than getting across Snell’s law, the concept of the mole and the fundamentals of Mendelian inheritance. Pupils ask about genetically-modified food, the greenhouse effect and faster-than-light travel, but few of us feel equipped to deal with all of these topics.

As scientists and teachers, we gradually accrue a great background of ideas, anecdotes, examples, tips and tricks which bring the subject alive for us and for our pupils. To do this across all three main areas of science is quite a challenge.

A new project from the Association for Science Education attempts to come to the rescue. With fellow-editors Michael Reiss and Bob McDuell and a team of writers and advisers, I have been developing three teaching guides which are intended to help all science teachers extend their teaching repertoire in all aspects of science. There are three titles in the ASEJohn Murray Science Practice series; Teaching Secondary Biology has just been published and the chemistry and physics titles will follow in December. Our work has been supported financially by the Institution of Electrical Engineers and ESSO, two organisations for whom a steady supply of enthusiastic and able young scientists and technologists is vital.

Each writer has taken a small topic area and suggested a teaching sequence which any teacher might follow to develop their 11 to 16-year-old pupils’ understanding. They have provided details of a sequence of activities, practical or otherwise, with a discussion of how these help to clarify concepts. Common misconceptions are highlighted, as are difficulties which may arise with particular pieces of equipment, and there are plenty of suggestions for using ICT resources. At all times the emphasis is on a clear, practical approach, with the underlying philosophy emerging from the practicalities.

We have also tried to emphasise ways in which teaching can be enhanced through activities and discussions which show science as a human activity with a history, and with a future that pupils may go on to contribute to themselves. These are the sorts of ideas which teachers gradually pick up throughout their teaching careers, through talking with other teachers, watching television programmes or reading around the subject.

The ASE’s aim is to encourage science teachers to help one another in their work. This series of handbooks is part of that project. We hope that their effect will be to help teachers get away from the idea that science is simply what appears in curriculum documents; it is a living, developing subject which impacts on all our lives, which can fascinate pupils and which can form the basis for their own future careers.

David Sang, series editor of theASEJohn Murray Science Practice series, is a science teacher and freelance author