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ACQ
Volume 13, Number 3 2011
ACQ
uiring Knowledge in Speech, Language and Hearing
subject to sometimes rapid change over time and can be
very difficult to judge. This issue presents us immediately
with a dilemma. If we try to produce the evidence based
on the usual criteria, we run the risk of not finding strong
evidence due to the inherent difficulty of running large group
studies, and therefore making our arguments look weak.
We also may find ourselves concentrating on the evidence
that is of least value, that is, those aspects which can be
subjected to large group similarities, when the main interest
is in variation.
Not only do the levels of evidence downplay the
significance of the lower levels, they fail entirely to deal
with qualitative data. An important aspect of evidence
based practice and research is considering the client and
family preferences and needs, and with this aim, the client
experience should form a major part of the research. Much
of this research, along with much “outcome” research,
should be qualitative (Kovarsky & Curran, 2007). However,
this research is sparse at best, and discounted even when
it is conducted and published. The positivist and therefore
culture-bound value system bound up in the levels of
evidence is also incompatible with cultural competence
perspectives, and needs ongoing critical scrutiny (Martin,
2009; Kovarsky & Curran, 2007).
Clinical bottom line
After finding and reviewing the evidence, weighing up both
its strengths and limitations, you draw a number of
evidence based conclusions to guide your practice and
thinking around this complex issue. Reaching a clinical
bottom line is important to be able to challenge the current
perspectives of your colleagues and the prevailing
monolingual model of practice. Guided by the evidence, the
key findings that you want to communicate are:
•
Children with language difficulties learn bilingually at
least as successfully as monolingually
. The intervention
studies reviewed here have indicated that when
language intervention is provided to bilingual children
in both languages, the children were capable of
learning the two languages to at least as good a level
as one, and there is some evidence to suggest their
achievement can be superior in bilingual intervention
(Kay-Raining Bird et al., 2005; Seung, Siddiqi, & Elder,
2006; Thordardottir et al., 1997; Tsybina & Eriks-Brophy,
2010; Waltzman et al., 2003; Wauters et al., 2001).
Of particular importance is that there is no evidence
supporting the argument that performance is worse as
a consequence of bilingual intervention compared to
monolingual.
•
Use bilingual clinical intervention, rather than just
encourage bilingualism
. Kohnert (2010) concluded that
systematic support for the home language(s) of young
children with language impairment is critical to the long-
term success of language intervention. She holds that
encouragement of home language use is not going far
enough, and fails to recognise the significance of the
child’s social, emotional, and cognitive development
taking place within the cultural context of the family. SPs
not only can, but should conduct bilingual interventions.
•
Clinicians can conduct interventions when they do not
speak all the languages competently
. It is evident that
a range of teamwork options are available that can
support a shift away from monolingual practice. Family
involvement is consistent with family-centred practice
principles and the research suggests that children
successfully learn language targets with parent-based
Another area of related evidence comes from a larger
body of research regarding bilingual education. This line
of research provides insight into the nature of language
learning associated with bilingualism. Slavin and Cheung
(2005) reviewed 17 studies across a range of bilingual
education models (mostly involving Spanish-English
bilinguals), concluding that “bilingual instructional models
[produced more favourable learning] over those that
eliminated [the] native language” (p. 280). The conclusion
was that the evidence is mounting in favour of bilingual
learning producing superior results for bilingual children,
even when the second language is dominant in the
education system. The research confirms that maintenance
in the first language is a predictor of future proficiency in
the second language as well as a powerful tool to assist
in the transfer of literacy knowledge from one language to
the next. Carlo et al. (2004), Combs, Evans, Fletch, Parra,
and Jimenez (2005), and Rolstad, Mahoney, and Glass
(2005) are other useful sources for this related evidence.
Furthermore, the benefits of bilingual education models are
likely to apply to children with language difficulties as well
(Culatta, Reese, & Setzer, 2006).
The problem of “evidence”
In complex areas, such as child language and
multiculturalism, building a body of evidence that adheres
to the NHMRC standards is problematic. The levels of
evidence tables such as that of the NHMRC make
judgements about “strong” and “weak” evidence based on
medical models that require reduction to controllable
variables with tightly defined populations and simple
interventions. Such systematic control is not well suited to
child language difficulties, where clinical populations are
poorly defined, and where complex and variable
interventions are used (Law, Campbell, Roustone, Adams,
& Boyle, 2008). Furthermore, clinical principles in the field of
speech and language pathology favour adaptation of
interventions to individual needs (Speech Pathology
Australia Code of Ethics, 2008), which makes such
variables even harder to control. Pring (2004) indicated that
randomised control trials in the first instance are not
appropriate as we need to develop a strong body of
foundation research at the case-study and small control
group level. He outlined a progression, wherein specific
therapies are developed for well-defined groups, tested first
in small-scale efficacy then effectiveness studies, and
results disseminated to clinicians for clinical application,
before any larger scale studies should be attempted. Fey
(2006) made the point that “the motivation for higher level
studies and the justification for sponsoring them financially
generally comes from studies that have already produced
encouraging results using less costly, lower level research
designs [that were high in quality]” (p. 318). Certainly
premature RCTs may be conducted by glossing over
problems, resulting in unusable results, such as could be
said of Glogowska, Roustone, Enderby, and Peters (2000).
Another incompatibility that emerges is that cultural and
linguistic diversity is about variation from the norm, whereas
the evidence level system is about the norm and about
subsuming variation within a group to produce statistically
robust results over large numbers. But the concept of
“normal” populations of minority groups within a dominant
culture, especially recent migrant or refugee groups, is
problematic. Types and degrees of bi-or multilingualism
vary, the amount of identification and practice of originating
culture to dominant culture varies, and both of these are