Intervention for Dyslexia - The British Dyslexia Association

eading accuracy 0.80 and for reading comprehension 1.86. However, these figures
should be interpreted with caution since sample size, severity of difficulties and length of
intervention have not been factored in. Nevertheless, they give some indication of the
degree of impact one might expect from phonological approaches that fall within the
category of secondary intervention. The most effective of these studies were found to
share the following essential elements:
Explicit training in phonological awareness
Strong focus on phonological decoding and word-level work
Supported and independent reading of progressively more difficult texts
Practice of comprehension strategies while reading texts
Instruction which is systematic and intensive, i.e. given either daily or in several
sessions per week over several weeks, with a target of between 20 and 40 total
hours of instruction.
Long-term studies show that systematic phonological secondary interventions continue
to have benefit for the literacy development of most children, especially for those who
show good growth during the intervention. However, a proportion – probably between
1.5% and 3% – of all children will nevertheless remain below target levels and will thus
require further or continuing intervention.
2.5 Tertiary intervention studies
Torgesen (2000) has estimated that between 2% and –6% of children would remain
poor readers even if secondary interventions were available to all who needed them.
However, Mathes et al. (2005) have estimated this group at less than 1% of all children.
Whatever the size of this group, it is these children who will require tertiary intervention.
The following subsections review the principal studies of intensive phonological
intervention with pupils from 4 th grade and above. The results of these studies are
summarised in Table 4. However, the averages shown in the table should be interpreted
with caution since sample size, severity of difficulties, and length of intervention have
not been factored in. Nevertheless, they give some indication of the degree of impact
one might expect from phonological approaches that fall within the category of tertiary
intervention. These studies raise several critical issues, which are discussed in Section
2.9.
2.5.1 Torgesen, Alexander et al. (2001)
Torgesen, Alexander, Wagner, Rashotte, Voeller, Conway and Rose (2001) studied 60
children in 4 th grade who had severe reading disabilities. Their mean age was 9.8 years
and 73% were boys. All the children had been identified by their teachers as having
serious difficulty acquiring word-level reading skills, and their measured word attack and
word identification skills were found to be at least 1.5 standard deviations below ageappropriate
levels. All had verbal IQ above 75 (mean VIQ 93; mean FSIQ 96) and had
poor phonological awareness. Hence, although these pupils were not explicitly described
as having dyslexia, it is highly likely that most, if not all, would be classed as dyslexic.
The children were randomly assigned to one of two direct instructional conditions:
40 Intervention for Dyslexia