Background: While practitioners are increasingly asked to be mindful of the evidence-base
of intervention programmes, evidence from rigorous trials for the effectiveness of
interventions that promote oral language abilities in the early years is sparse.
Aims: This study evaluates the effectiveness of a language intervention programme for
children identified as having poor oral language skills in preschool classes.
Methods & Procedures: A randomised controlled trial was carried out in 13 UK nursery
schools. In each nursery, eight children (N = 104, mean age = 3 years 11 months) with the
poorest performance on standardised language measures were selected to take part. All but
one child was randomly allocated to either an intervention (N = 52) or a waiting control
group (N = 51). The intervention group received a 15-week oral language programme in
addition to their standard nursery curriculum. The programme was delivered by trained
teaching assistants and aimed to foster vocabulary knowledge, narrative and listening skills.
Outcomes & Results: Initial results revealed significant differences between the intervention
and control group on measures of taught vocabulary. No group differences were found on
any standardised language measure; however there were gains of moderate effect size in
listening comprehension.
Conclusions & Implications: The study suggests that an intervention, of moderate duration
and intensity, for small groups of preschool children successfully builds vocabulary
knowledge, but does not generalize to non-taught areas of language. The findings strike a
note of caution about implementing language interventions of moderate duration in
preschool settings. The findings also highlight the importance of including a control group in
intervention studies