The Text Checker aims to help teachers avoid text that pupils cannot understand. It is based on Edward Fry's readability graph, which looks at the number of syllables and sentences in a 100 word sample to give a notional reading age. It is presented in a booklet and an attractive set of laminated cards.
Unfortunately, Fry's system is not based on analysis of what children of a given age can read, but on what he thought they could read, and his method is too simple.
A large number of simple words, for example, do not necessarily make a sentence difficult, while a few unfamiliar words may make it impossible.
The system is particularly unreliable for dialogue, which often has short sentences, and it can lead to unchallenging material that does not build literacy skills. What's more, Fry's graph, with instructions, is available free on the internet.
Also included are sample texts for various reading ages and hints on promoting reading.