 and that from age 11 writing,
itself, would show the strongest relationships with subsequent writing
performance. No model including reading at age 8 or reading at age 11
fit the data; however, a longitudinal model including vocabulary at age
8 having an indirect effect on writing provided a good fit. The path
analysis in Figure 3 indicates direct effects of reading ([beta] = .27),
spelling ([beta] = .34), and writing ([beta] = .32) at age 14 with
writing at age 16. Oral language skills had an indirect effect through
reading at age 14 ([beta] = .34) and writing at age 14 ([beta] = .25).
Vocabulary at age 8 revealed indirect effects on writing through
vocabulary at age 11 ([beta] = .75). Moreover, vocabulary at age 11
revealed indirect effects on writing at age 16 through oral language at
age 14 ([beta] = .51). More important, the indirect effect of writing at
age 11 was evident through spelling at age 14 ([beta] = .55) but not, as
predicted, writing at age 14 ([beta] = .16). The goodness of fit
measures indicated a good fit: [chi square] (16) = 11.350, p = .79,
RMSEA = .00, CF1 = 1.000. We also tested models examining alternative
directions of effect and models including nonverbal ability and reading
comprehension to explore a better fit. These alternative models did not
provide a fit with the data.
We examined longitudinally the writing skills of a cohort of
students with a history of SLI to age 16. We examined measures of
language and literacy assessed both longitudinally and concurrently to
establish their relative contribution to written text production. The
students in this study continued to experience specific difficulties
with language and literacy. Production of written text continued to be
an area of marked vulnerability, with writing scores being the lowest
standardized score of the receptive language and literacy measures.
Moreover, during their teenage years the students' writing skills
decreased relative to standardized norms. Thus, the current data
contrast with data in the elementary years for children with SLI where a
relative improvement in the production of written story composition has
been noted (Fey et al., 2004). These differences are important to
address. The decreases in student performance on written measures may
reflect specific language difficulties. For typically developing
children, increasing language and literacy skills support later
development of writing; for those with continued difficulties these
resources are not available. In conjunction it is important to consider
the specific support provided to children when developing their written
language skills. This decrease in writing skills occurred at the time
(age 11) when, in the United Kingdom, it is expected that students have
mastered the basic skills in reading and writing, have moved towards the
analysis of genres, are writing with technical accuracy, and able to
organize text into planned and coherent sequences (Department for
Children, Schools and Families, n.d.)--a major challenge for the
students in this study.
WOLD (Wechsler, 1996) provided the tool for comparing performance
on writing dimensions over time. Results on the WOLD subscales at age 16
were consistent with assessments at previous points in development
(Dockrell, Lindsay, Connelly, et al., 2007; Mackie, 2007): Performance
was reduced across all subscales, but the poorest performance was
evident in measures of sentence structure, ideas and development, and
vocabulary. The factor analysis of the WOLD subscales provided evidence
that at this point in development, the students' written work could
be captured by a single dimension. This differs from the patterns at age
11 (Dockrell, Lindsay, Connelly, et al., 2007) and age 14 (Dockrell
& Connelly, 2007), where two different dimensions underpinned
performance on the WOLD: semantics and rules. This single factor for the
WOLD is, however, consistent with data for younger (age 11) typically
developing children (Connelly & Dockrell, 2008) and suggests that
for students with a history of SLI the coordination of idea generation
