s difficulties with
subcomponents of the language system (Leonard). Measurements that tap
into children's proficiencies with phonological processing,
sentence recall, nonword repetition, and tense marking have all
demonstrated high levels of specificity and sensitivity in
differentiating children with SLI from their typically developing peers
(Conti-Ramsden, Botting, & Faragher, 2001; Ellis Weismer et al.,
2000). Although conventionally identified by discrepancy criteria,
children with SLI are heterogeneous in their profile of language
impairments and in terms of nonverbal ability (Botting, Faragher,
Simkin, Knox, & Conti-Ramsden, 2001). Patterns of performance also
vary over time (Botting, 2005; Conti-Ramsden & Botting, 1999). For
many young people with SLI, difficulties with spoken communication
skills persist into adolescence (Beitchman, Wilson, Brownlie, Waiters,
& Lancee, 1996; Botting et al.; Stothard, Snowling, Bishop,
Chipchase, & Kaplan, 1998) and adulthood (Clegg, Hollis, Mawhood,
& Rutter, 2005; Johnson et al., 1999). Older students continue to
experience difficulties with reduced vocabulary levels (Johnson et al.);
accurate use of verb morphology (Clahsen, Bartke, & Gollner, 1997);
and some syntactic structures (Norbury, Bishop, & Briscoe, 2001).
These linguistic deficits have marked effects on the processing of
written text (Bishop & Snowling, 2004), resulting in difficulties in
both word reading and comprehension (Catts, Fey, Tomblin, & Zhang,
2002; Stothard et al., 1998). As with linguistic performance there is
considerable variability within the population on these measures, only
some of which is explained by language competence and cognitive skills
(Young et al., 2002). Variations in phonological and nonphonological
language skills relate to different patterns of reading behavior (Bishop
& Snowling). Phonological processing skills are closely related to
reading decoding (Castles & Coltheart, 2004) and spelling
(Caravolas, Hulme, & Snowling, 2001), whereas measures of receptive
language have been associated with poor reading comprehension (Nation,
Clarke, Marshall, & Durand, 2004). Both receptive and expressive
vocabulary are related to reading performance (Ouellette, 2006;
Tannenbaum, Torgesen, & Wagner, 2006; Wise, Sevcik, Morris, Lovett,
& Wolf, 2007).
Specific relationships between oral language competence and the
production of written text have been reported both for children with
continuing and those with resolved language problems, leading to the
hypothesis that written language can be conceptualized as a window into
residual language problems (Bishop & Clarkson, 2003; Fey, Carts,
Proctor-Williams, Tomblin, & Zhang, 2004). Phonological processes
directly impact children's spelling, a prerequisite to extended
text generation (Berninger, Abbott, Whitaker, Sylvester, & Nolen,
1995). Wider oral language comprehension skills have been implicated as
important factors in the children's text production (Bishop &
Clarkson; Cragg & Nation, 2006; Dockrell, Lindsay, Connelly, &
Mackie, 2007). Vocabulary appears to provide a building block for
written language (see Green et al., 2003). A range of lexical items
provides children with the ability to build a text and provide the basic
infrastructure of text meaning (see Berninger et al., 1997).
A recent comparative study of adolescents with dyslexia, those with
language impairment, and typically developing matched adolescents
demonstrated the ways in which different profiles of language skills can
impact writing performance (Puranik, Lombardino, &Altman, 2007).
Participants with SLI (but not dyslexia) produced fewer words and
numbers of ideas than typically developing peers. In contrast, both
students with dyslexia and students with language impairment produced
more spelling and grammatical errors than their matched peers. Puranik
and colleagues argued that the difference between the performance of
these two groups was due to the difficulties experienced by the students
with language impairment in the nonphonological dimensions of text
Difficulties with literacy c