Science teachers arrived in Liverpool for the Association for Science Education’s annual conference this month with renewed vigour. Perhaps it was the sea air or the friendly Scouse welcome - either way the Merseyside campus had a definite buzz, and the publishers exhibiting in the crypt of the huge cathedral must have enjoyed the three-day meeting.

With a firmly entrenched national curriculum and an equally entrenched use of the word “deliver” as the modern metaphor for teaching, teachers and publishers deserve praise for their continuing ability to enthuse about resources.

Although 10 years of the national curriculum have stifled some creativity and left little room for deviation or extended reading, there remains a remarkable diversity among published materials - schemes, textbooks and now multimedia.

At primary level, Ginn has completed Star Science, with guidance for the non-specialist. Oxford University Press has some excellent reading material for science, and Longman’s Science Connections and Stanley Thornes’s Primary Science were also on show.

Teachers of key stage 3 enjoy a wide choice of materials, including Heinemann’s Science Now!, Cambridge’s Core Science, Hodder amp; Stoughton’s Science Scene(with useful new support packs), Stanley Thornes’s Spotlight Science, Nelson’s Go for Science! and Collins’s Science Connections.

Key stage 4 teachers have an even wider range, to choose from, with some books written for separate sciences and others for the dual or single awards. Post-16 students have a choice of texts, some for A-level, with a smaller number (mostly from Heinemann) for GNVQ.

At A-level, well-written texts from Cambridge, Nelson and Collins cater for modular and separate sciences.

An exhibition accompanying the excellent Science Teacher Festival, launched to celebrate 100 years of science teacher associations, showed how the use of text and image in published resources has been transformed. Any teacher who last attended an ASE meeting in the 1970s would be astounded by the changes.

In the Sixties it was discovery learning and Nuffield Science; in the Seventies it was the process movement and Warwick Science. The constructivist approach, which starts with pupils’ own understanding, influenced today’s Oxford Science Programme, while anti-sexism and anti-racism campaigns have had a widespread impact.

The drive for increasingly accessible text, based on a host of crude readability formulae, together with the growing use of colour illustrations, the reduced number of words per page, the double-page spread, and the increased size and variety of typefaces have all helped revolutionise the science textbook.

While many of these changes are welcome, perhaps it is time to look critically at textbooks that are little more than comic strips, where over-reliance on illustrations is as confusing as the text-laden publications of the past and where the lack of double-page spreads limits opportunities for sustained reading.

According to one major publisher at this year’s meeting, editors now tell authors to write no more than 200 words for each side of a double-page spread. How will this prepare pupils to be critical and reflective readers of science in newspapers, magazines or journals?

Another trend, much in evidence in Liverpool, is the blurring of boundaries between publishers and resources.

Channel 4, for example, produces valuable books and study guides to go with excellent programmes such as Scientific Eye. It has also done its homework on Internet links - Channel 4‘s own Web site and printed material will give teachers and pupils Internet addresses they can follow up for extension or project work.

Similarly, the main CD-Rom producers for science - BTL, Anglia Multimedia and New Media - all produce useful printed material to go with their CD-Roms. All three companies have interesting new titles - BTL has Core Chemistry, New Media has Electrochemistry and Anglia is offering Cell City for key stages 3 and 4.

Stanley Thornes has several CD-Roms that link with its books (most notably for biology at A-level), while Routledge now publishes a CD-Rom on electricity and magnetism for the primary phase.

Given this wealth and diversity of material, how do we choose the “right” textbook or scheme. Basic criteria include the appropriate language level, scientific accuracy and curriculum fit. After that, it depends on the needs of the teacher and school.

Textbooks, after all, have many uses - as guidance for practical work, “lesson fillers”, sources of homework, bald statements of “the facts”, cover for absent teachers, a crutch for the non-specialist, revision guides and, just occasionally, as a source for an extended reading activity in a science lesson.

After my son’s first day at comprehensive school, he came home and told me excitedly his science class had been using lots of my science textbooks.What for, I asked? He said six of them were used to prop up a wooden ramp so the pupils could run trolleys down it - horses for courses.

Jerry Wellington is a reader in science education at the University of Sheffield