Esso claims that a petrol station trip will help five to seven-year-olds with maths, science and technology. The company’s Evolution of the Tiger strays even further into the field of marketing, promising to teach the development of its tiger advertising and explain “why Esso became involved in Tiger conservation”.

But not all resources go down this route. For instance, ICI’s Sense of Smell Internet resource is a straightforward teaching aid on the science of perfumes and fragrances - ICI’s only presence is a masthead logo.

Because of the vast array of resources on offer, some companies now produce guides which have been audited to ensure that the contents comply with the national curriculum. For instance, guides produced by Resources Plus cover all national curriculum subjects, indicate whether the resource is free or paid for (material for schools is usually heavily subsidised), list the target age group, and give a summary of contents and the medium (for example, CD-Rom, book, video).