Intervention for Dyslexia - The British Dyslexia Association

Vaughn & Linan-Thompson, 2003). Overall, these findings suggest that provision of
secondary intervention by non-teachers should be more closely examined, as it can be
less costly than intervention given by teachers. One might expect teachers to be more
flexible and responsive to individual differences in learning needs, and thus perhaps
more appropriate for the most severely impaired readers or those unresponsive to other
methods, i.e. in tertiary intervention.
Table 3. Summary of results of some of the principal secondary interventions (effect sizes of
gains in reading when compared with untreated controls)
Author(s) and
date
Swanson (1999) Meta-analysis of 92
studies
Torgesen et al.
(1999)
Notes Phonic
Decoding
PASP group compared
with controls
Ehri et al. (2001) Follow-up 4–12 months
(mean)
Vadasy et al.
(2002)
Vadasy et al.
(2002)
Elbro and
Petersen (2004)
Frost & Sørensen
(2007)
Ryder et al.
(2008)
Ryder et al.
(2008)
Phonological group
compared with controls
Reading
Accuracy
Comprehension
1.06 1.15
1.04 0.71 3.45
0.44
1.18
Follow-up after 2 years 0.40
Follow-up after 7 years 0.48 0.53
Norway 0.87 1.20
New Zealand 1.69 0.88 0.98
Follow-up after 2 years 0.81
Average* 1.02 0.80 1.86
* Not weighted for sample size
2.4 Conclusions on secondary intervention
A wide range of studies using phonological approaches to secondary intervention has
been presented, and all point to the benefits of such intervention for children with
dyslexia or LD, even when instruction is provided by non-teachers, provided they have
received adequate training, and even when instruction is given to small groups of
children (up to 4–5 children per group). The results of some of the principal studies in
which comparison with controls was made and in which reading was assessed are
summarised in Table 3. The average effect size for phonic skills was 1.02, for word
Intervention for Dyslexia 39