Intervention for Dyslexia - The British Dyslexia Association

Against the many advantages of computer-based assessment must be set its limitations.
Computer technology is not yet sufficiently advanced to permit the use of direct speech
input into the computer for assessment purposes because current technology generates
error frequencies that would undermine the reliability of the test. Phonological
processing and word reading are fundamental areas of deficit in dyslexia, and
assessment of either of these skills normally requires an oral response from the child.
This technological limitation is therefore a serious one for computer-based tests. It is
anticipated that within a few years voice input technology will be adequate for this task,
but in the meantime designers of computer tests attempt to circumvent this problem by
using multiple-choice items (which changes a word reading or phonological task from
production to the somewhat easier task of recognition) or, in the case of reading, using
sentence completion or Cloze tasks, which involve comprehension and which
consequently are not pure measures of reading accuracy. In view of these problems,
some teachers and psychologists may feel that when assessing phonological and word
reading skills the conventional approach is still to be preferred; others may feel that the
advantages and greater practicality of computer-based screening make the acceptance
of these limitations for the time being a price worth paying.
The two computer-based screening tests for dyslexia are the Dyslexia Screener (Turner
& Smith, 2004) and Lucid Rapid Dyslexia Screening (Singleton, Horne, Leedale &
Thomas, 2003). Both these tests provide automatic scoring in standardised score form
and automatic interpretation of results.
The Dyslexia Screener is designed for children aged 5–16 years and comprises the
following subtests, which in total take about 30 minutes for the average child to
complete:
Non-verbal reasoning
Phonics
Spelling
Visual search
Reading
Verbal reasoning.
The decision process used by the Dyslexia Screener is largely based on discrepancy
between intelligence (verbal and non-verbal reasoning subtests) and performance on
the literacy tests (reading, spelling, phonics) (see Section 4.1.1 for a discussion of the
discrepancy criterion in the identification of dyslexia). It incorporates a version of
Turner’s Dyslexia Index (see Section 4.3.2), but whereas Turner (1997) advocates using
a total of at least 13 tests to calculate the Dyslexia Index (six ability tests, four
diagnostic tests, and three achievement tests), the Dyslexia Screener comprises only six.
Expected reading and spelling scores are estimated by the program using the combined
ability score (derived from verbal and nonverbal reasoning), and based on correlation
coefficients typically reported in the psychological literature for the relationships
between literacy and general ability. And whereas Turner (1997) includes several
memory tests in his analysis, it is notable that, unlike all the other dyslexia screening
and profiling tests considered in this Chapter, the Dyslexia Screener does not contain
any tests of memory or of phonological processing. Arguably, this deficiency weakens its
capability to identify children with dyslexia, particularly if they are of below average
intelligence and a discrepancy is not apparent.
Intervention for Dyslexia 89