Intervention for Dyslexia - The British Dyslexia Association

and effect sizes of 0.55 for reading and 0.27 for spelling were calculated by Brooks. This
is one of the few studies to have followed the children up after the intervention: both 10
weeks and six months later they had continued to improve. Another study carried out
over four weeks in Wiltshire, with 149 poor readers in years 3–6, produced ratio gains of
7.7 for reading comprehension and 6.2 for spelling.
In an evaluation of Wave 3 interventions carried out by Bristol Learning Support Service
(2005), a total of 60 pupils in 13 primary schools used AcceleRead AcceleWrite. 88% of
these children were on the SEN register, including 5% with statements of special
educational need and 43% at School Action Plus, suggesting that most of these children
were considerably disabled in reading. Standardised assessments were carried out using
the NFER Individual Reading Analysis, Neale Analysis of Reading Ability (NARA), and
Vernon Spelling. The results (after an estimated eight weeks of intervention) revealed
ratio gains of 2.3 for reading accuracy, 2.9 for reading comprehension and 2.0 for
spelling.
3.3.2 Interactive Assessment and Teaching (IA&T) 8
Nicolson, Fawcett, Moss, Nicolson & Reason (1999) screened classes in four UK infant
schools to identify children most at risk of reading failure on the basis of their WORD
reading and spelling scores (N=62, mean age 6 years 0 months). These children were
also assessed on the Dyslexia Early Screening Test (DEST) and the British Picture
Vocabulary Scale (BPVS), a test of verbal intelligence. The intervention group was given
an adaptive, curriculum-based support programme with the emphasis on word building
and phonics skills, based on the Interactive Assessment and Teaching (IA&T) reading
programme (Reason & Boote, 1994). The intervention was delivered by trained
researchers to children in groups of four for two 30-minute sessions per week for 10
weeks (10 hours total intervention).
The intervention group improved significantly in reading and spelling standard scores
(effect size 0.94 for reading and 0.95 for spelling) compared with a group of control
children (N=38) that had been matched for age and reading performance, the latter
making no overall improvement. A follow-up six months later showed that the gains
made by the intervention group were maintained in spelling but largely lost in reading
(although the children in the control group had slipped back even more). Despite the
clear progress of the intervention group overall, 25% remained ‘problem readers’ (i.e.
with reading still at least 6 months behind expected levels).
The authors propose the following three-stage intervention strategy: (i) children at risk
of reading difficulties are identified before 6 years; (ii) at-risk children are given a smallgroup
intervention programme for 3–4 months; (iii) children still failing to make progress
should then be given continuing targeted additional support. They also note that the
per-child costs of this study are about 3.5 hours of teacher time, compared with the
8 Note that in all the papers reported in this subsection, the authors have calculated effect sizes
separately for each group, and not on the basis of difference in gains between the intervention
group and the control group as advocated by Brooks (2007). The latter method will generally
result in somewhat lower effect sizes. For example, in the paper by Nicolson, Fawcett, Moss,
Nicolson & Reason (1999) the authors quote effect sizes of 0.94 for reading and 0.95 for spelling,
whereas Brooks (2007) reports somewhat lower effect sizes for this study (0.72 for reading and
0.56 for spelling).
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