The difficulties of diagnosing dyslexia

17th March 2006 at 00:00
Dyslexia? Assessing and reporting

By Gill Backhouse and Kath Morris

Hodder Murray pound;15.99

Cheap and easy

Dyslexia screening test - Junior (DST-J)

Dyslexia screening test - Secondary (DST-S)

By Angela Fawcett and Rod Nicolson

Harcourt Assessment pound;125 each, plus VAT

If this were a guide to literacy assessment, it would have much to commend it. It discusses a wide range of tests and techniques, and the authors know how to make assessment positive, identifying strengths and talents as well as difficulties.

Some of their practical hints are surprisingly effective. Sitting at right angles to the client, for example, provides the best view of both the material and the person's response to it. There is good guidance on writing reports, and on obtaining contextual information, including the observations of parents, particularly mothers.

At the heart of the book, though, is the question of how to determine whether a learning difficulty is or is not dyslexia, and this is contentious. The authors list 57 tests that can contribute to assessment, with brief comments on each. Some of their remarks, including those on motor tests for young children, are incisive and helpful. Others do not say enough about what a test actually tells us, how reliable its scores are, or how far it succeeds in its aim of being diagnostic. There is heavy reliance on weak decoding of phonic patterns and manipulation of language in spoonerisms as evidence of dyslexia, when these may equally well indicate some earlier gap in teaching or a weakness in handling this type of problem.

The guide should also have said more about screening for visual difficulties, as these can produce a similar pattern to dyslexia.

The worked examples combine test analysis with other evidence, such as weak literacy in the family, and most provide good practical guidance. None states that the person "is dyslexic", they use instead, terms such as "has a dyslexic profile", or "difficulties ... typical of dyslexia". These are an honest reflection of the evidence, but also of its limitations. As Nick Peacey's chapter shows, increasingly serious legal implications hinge on dyslexia assessment, therefore we have a clear need for an approach that will identify the condition and avoid confusion with other literacy problems. New developments in brain scanning that would make this possible may be closer than we think.

These tests aim to save money, improve access to assessment and empower teachers by making dyslexia assessment available without the delay and expense involved in consulting a psychologist. As psychological assessments cost more than twice the price of one of these kits, this seems a good idea, provided the test is reliable and easy to use.

The first edition sold 3,000 copies and has been recognised as an assessment instrument by the DfES. The secondary version has been developed with a view to the assessment needed for exam concessions.

Both tests have 12 activities, covering a range of literacy and thinking skills. These include the speed of naming simple pictures, manual dexterity (threading beads), postural stability, breaking words down into their constituent sounds, nonsense words, and speed tests of reading and spelling.

The secondary version includes a test of "non-verbal" reasoning, based on identifying patterns in shapes, although the term "non-verbal" does not take account of the use of language in users' minds as they analyse patterns in the shapes.

It is also a pity that the authors have relied on the psychologists'

hackneyed test of remembering sequences of numbers (in this case, to be repeated backwards) as their only test of memory. This activity has nothing to do with the intellectual processes of reading.

The authors say the tests should take roughly 30 minutes. As some need only one minute, this seems a reasonable goal once the tester knows the material thoroughly.

Results have been standardised well and will reliably show if a particular score is out of line, either with those of most children of the same age or with a child's other scores.

This can be useful, but to go on to say that a child is or is not dyslexic is a big step, and one the authors do not take. Instead, they say that a child is at mild, moderate or high risk "of dyslexia or other reading difficulties".

In fairness, most psychologists also shrink from an unequivocal diagnosis of dyslexia - they find the phrase "consistent with" very handy - but the terminology used here simply will not do.

If a child is not at risk of reading difficulties, then why use the test? Not, I hope, to get 15 minutes' extra in exams.

John Bald is a literacy consultant

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