11/19/2010
Acknowledgements
Measures of Expressive
Vocabulary in Children with
Do n Syndrome
Down
S ndrome
Yolanda Keller-Bell, PhD, CCC-SLP
University of Georgia
November 19, 2010
ASHA 2010 Philadelphia, PA
Session 1613
Background

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Preparation of this presentation was
supported by grant awards from the National
Institutes Health and the University of
Georgia Research Foundation.
Many thanks to the participants and their
families.
Graduate Assistants: Donna Brooks, Brooke
Davis, Sara Levis, Allison Hyde, and
Alexandra Betley for their data analysis and
coding.
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ASHA 2010
Philadelphia, PA
Session 1613
Expressive Language
Seventy-six percent of SLPs report that they
work with children with intellectual disabilities
(ASHA, 2010).
Down syndrome is one of the most common
intellectual disabilities found in the United
States.
Individuals with Down syndrome exhibit
significant delays in communication ability,
particularly in expressive language.
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Philadelphia, PA
Session 1613
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Prior research has found greater delays in expressive language than
receptive language in regards to cognitive level expectations,
particularly morphological and syntactic development
The results regarding expressive vocabulary have not been
consistent.
 Miller (1988): Expressive vocabulary of preschoolers with Down
syndrome was delayed relative to nonverbal cognitive level, as
measured by language sampling.
 Laws and Bishop (2003): No significant difference between older
school-age children and adolescents from nonverbal MAmatched controls on the Expressive Vocabulary subtest of the
Kaufman Assessment Battery for Children.
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ASHA 2010
Philadelphia, PA
Session 1613
Purpose
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Chapman et al. (1998) Children and adolescents with
Down syndrome had more limited vocabulary on
language samples than did non-verbal cognitive
matched children.
Hicks et al (2002): In a longitudinal study,
study initially
initially,
children with DS showed an advantage on standardized
measures of vocabulary when compared to children with
SLI. However, the children with DS appeared to plateau
over time and the advantage disappeared.
Roberts et al (2007): Children and adolescents with DS
performed poorer on standardized measures of
vocabulary.
November 19, 2010
ASHA 2010
Philadelphia, PA
Session 1613
The purpose of this preliminary study was
examine the following questions:


Do children with Down syndrome differ from
nonverbal cognitive matches in their performance
on standardized and informal vocabulary
measures?
Do children with DS exhibit different types of
errors than nonverbal cognitive matches on the
Expressive Vocabulary Test?
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ASHA 2010
Philadelphia, PA
Session 1613
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Participants
Language Measures
Typically
Developing
(n=15)
p
10.13
8.38
4.48
.80
<.001*
4.8
.6
4.70
1.0
.70**
Down syndrome
(n=10)

Chronological Age
(years)
Mean
SD
Nonverbal Mental Age
(
(years)
)
Mean
SD


Nonverbal IQ
(Standard Score)
Mean
SD
Peabody Picture Vocabulary Test-III (Dunn &
Dunn, 1997) as a measure of receptive
vocabulary.
Expressive Vocabulary Test (Williams
(Williams, 1997)
as a measures of expressive vocabulary

58.10
16.44
103.20
12.77
<.001*
15.30
1.63
16.00
1.51
.277**
Examined the type of errors produced
Adapted scoring scheme from Ypsilanti et al
(2007) and McGregor et al (2002) studies.
Maternal Education
Mean
SD
*Significant if p<.05; **Statistically matched if p>.5 (Mervis & Klein-Tasman, 2004)
What else can you call a JET?
Semantic Errors:
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Types of Errors on EVT
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Perceptual misidentification led to an incorrect answer;
named something else in the picture
Examples: “Grass” or instead of “stone”
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Philadelphia, PA
Session 1613
Language Measures
Circumlocutions
 More than one word was used to describe the target
item. The child did not give the target word but gave
an accurate description of the object.
 Example: A synonym for “big”-“It’s like a grown-up” or
“Tall
Tall like a house”
house
Morphological Errors
 Incorrect responses caused by word morphology
 Example: A synonym for “done”- “finish” instead of
“finished”
Indeterminate: No response, unintelligible, refused to
respond (“Don’t know”)
November 19, 2010
The response was semantically related to the correct
answer
Examples: “Chair” instead of “couch”, “duck” instead of
“chicken”
chicken
Perceptual Errors:
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Session 1613
Types of Errors on EVT
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Language sample: Conversational sample
elicited in response to open-ended questions,
e.g. “Tell me about your family” and “What do
you like about school?”
y
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The Systematic Analysis of Language Transcripts
(Miller & Iglesias, 2008) was used for analysis.
Lexical diversity: Number of different words
divided by the total number of complete and
intelligible utterances.
Mean length of utterance in words (MLU-W).
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Reliability
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Results: Language Measures
Inter-rater agreement between two transcribers was
calculated on five of the children’s language
samples and error type on the EVT, chosen at
random.
P i tt
Point-to-point
i t agreementt on morpheme
h
and
d
utterance segmentation were 95% and 97%
respectively. Disagreements were resolved through
discussion.
All the test scorings were checked for accuracy by a
second scorer. Point-to-point agreement on error
type ranged from 92% to 95%.
ASHA 2010
Philadelphia, PA
November 19, 2010
Down syndrome
(n=10)
Typically
Developing
(n=15)
Typically
Developing
(n=15)
p
60.50
21.32
69.13
22.66
.321
44.80
15.08
51.60
15.91
.70
1.41
.39
2.09
.46
<.001*
2.96
1.64
4.48
1.37
<.024
PPVT-III (Raw Score)
Mean
SD
EVT (Raw Score)
Mean
SD
Lexical Diversity
Mean
SD
MLU-W
Mean
SD
*Significant if p<.0125
Session 1613
Results: Types of Errors on EVT
Down syndrome
(n=10)
Results: Types of Errors on EVT
p
Down syndrome
(n=10)
Typically
Developing
(n=15)
p
.60
1.29
1,47
1.73
.174
.30
.65
.27
.59
.900
2.60
1.86
1.67
1.72
.227
Circumlocution
Semantic
Mean
SD
2.00
2
00
1.34
2.33
2
33
1.80
6.20
3.04
5.93
4.20
.862
Perceptual
Mean
SD
.859
Mean
SD
Morphological
Mean
SD
Indeterminate
Mean
SD
*Significant if p<.01
*Significant if p<.01
References
Conclusions


Do children with Down syndrome differ from nonverbal
cognitive matches in their performance on
standardized and informal vocabulary measures?
 No significant group differences in raw scores on
EVT and PPVT-III, or MLU- Words.
 Children with Down syndrome had significantly less
lexical diversity.
Do children with Down syndrome exhibit different
types of errors than nonverbal cognitive matches on
the Expressive Vocabulary Test?
 No, the groups demonstrated similar types of error
patterns.
November 19, 2010
ASHA 2010
Philadelphia, PA
Session 1613
American Speech-Language-Hearing Association. (2010). 2010 Schools
Survey report: SLP caseload characteristics. Available from
www.asha.org/research/memberdata/SchoolsSurvey.htm.
Chapman, R. S., Seung, H. K., Schwartz, S. E., & Bird, E. K. R. (1998).
Language skills of children and adolescents with Down syndrome: II.
Production deficits. Journal of Speech, Language, and Hearing Research,
41, 861-873.
Dunn, L.M. & Dunn, D.M. (2007). Peabody picture vocabulary test, fourth
edition. San Antonio, TX: Pearson.
Laws, G., & Bishop, D. V. M. (2003). The comparison of language abilities in
adolescents with Down syndrome and children with specific language
impairment. Journal of Speech, Language, & Hearing Research, 46, 13241339.
McGregor, K, Newman, R., Reilly, R., Capone, N. (2002). The nature of wordfinding errors of preschoolers with and without word-finding deficits. Journal
of Speech & Hearing Research, 45, 998-1014 .
November 19, 2010
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Philadelphia, PA
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Mervis, C. B., & Klein-Tasman, B. (2004). Methodological Issues in GroupMatching Designs: α Levels for Control Variable Comparisons and
Measurement Characteristics of Control and Target Variables. Journal of
Autism and Developmental Disorders, 34, 7-17.
Miller, J. F., Nadel, L., & al, e. (1988). The developmental asynchrony of
language development in children with Down syndrome. In The
psychobiology of Down syndrome. (pp. 167-198): MIT Press, Cambridge,
MA,, USA.
Roberts, J., Price, J., Nelson, L., Burchinal, M., Hennon, E., Barnes, E.,
Moskowitz, L., Edwards, A., Malkin, C., Anderson, K., Misenheimer, J., &
Hooper, S.R. (2007). Receptive vocabulary, expressive vocabulary, and
speech production of boys with fragile X syndrome in comparison to boys
with Down syndrome. American Journal on Mental Retardation, 112, 177193.
Williams, K.T. Expressive vocabulary test, second edition. San Antonio, TX:
Pearson.
Ypsilanti, A., Grouios, G., Alevriadou, A., & Tsapkini, K. (2005). Expressive and
Receptive Vocabulary in Children with Williams and Down Syndromes.
Journal of Intellectual Disability Research, 49, 353-360.
November 19, 2010
ASHA 2010
Philadelphia, PA
Keller-Bell, Y.
Session 1613
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