Reading Working Papers in Linguistics 4 (2000) - The University of ...

R. INGHAM
good as their CA matches on this measure of a-structure performance, varying
the structure to suit the scene being depicted. This could suggest that a-
structure knowledge is acquired as part of grammatical development, rather
than being dissociated from it.
In fact, in the Schelletter et al. study, the children with a morphological
deficit also had a much greater lexical deficit as measured by BPVS scores
(av. 25 months versus av. 16 months) so their poor argument structure
performance may simply have been a reflection of the lexical deficit rather
than with the grammatical deficit. In the present study this issue was taken up
by looking at two SLI groups very sharply differentiated as regards lexical
knowledge. If argument structure alternations are a matter of lexical learning,
then we would expect the LD group to have a deficit in argument structure
realisation as compared with vocabulary matches, but the NLD group to have
no such deficit as compared with their matches.
3. Methodology
The performance of these four groups was investigated on elicitation tasks
designed to reveal aspects of the grammatical and lexical abilities of preschool
children. These are described in detail in Fletcher et al. (submitted) &
Ingham et al. (1999). These involved describing two series of video scenes.
The first task used a commercially available video from the Pingu series,
which has no words but plenty of actions. It was played twice. The
investigator described events in the present tense the first time the video was
shown. The second time, children re-narrated the story in the past tense. This
task allowed certain grammatical areas associated with finiteness, such as
tense form, to be investigated, and was chosen to allow plenty of
opportunities for the use of regular past verbs.
The second task used a video especially prepared for the research
project, and featured scenes designed to illustrate actions denoted by verbs of
particular interest for their argument structure. Five verbs which were
alternated by 50% or more of adult controls were scored for the use of
alternations by the 40 SLI and LN children. These were open, move, bounce,
give and rub. The child was supplied with the target verb, and asked to say
what happened in the video scene. For each verb two scenes were included in
the video; in each scene the events portrayed were such as to favour the use of
one alternant rather than the other. For example, in one scene for bounce an
52