It is no surprise that it is proving difficult to design a single-level test (“Snag hits development of ‘when ready’ tests”, TES, October 10). Why? First, the idea of “levels” is flawed. (How can you “level” English, for example?) Second, the level descriptors on which any test has to be based are unclear, often vague and capable of being interpreted in a variety of ways.

Surely this throws into doubt not only the “when-ready” tests, but also the whole notion of level-based tests at age 11, now that those at age 14 have been abolished?

Despite attempts to salvage its damaged credibility, the testing regime will never be “ready” to fulfil the claims of its supporters.

Professor Colin Richards, Spark Bridge, Cumbria.