examining the appropriateness of the ppvt-iii as a measure of vocabulary development in ...

125 Pages·2010·1.52 MB·English

by  Amy Platt

EXAMINING THE APPROPRIATENESS OF THE PPVT-III AS A MEASURE OF
VOCABULARY DEVELOPMENT IN LINGUISTICALLY DIVERSE KINDERGARTEN
CHILDREN

by

Amy Elizabeth Platt

A thesis submitted in conformity with the requirements
for the degree of Doctor of Philosophy
Department of Human Development and Applied Psychology
Ontario Institute for Studies in Education
University of Toronto

© by Amy Elizabeth Platt 2010
EXAMINING THE APPROPRIATENESS OF THE PPVT-III AS A MEASURE OF
VOCABULARY DEVELOPMENT IN LINGUISTICALLY DIVERSE KINDERGARTEN
CHILDREN

Doctor of Philosophy 2010
Amy Elizabeth Platt
Department of Human Development and Applied Psychology
University of Toronto

Abstract
In order to evaluate the appropriateness of a standardized vocabulary measure for
linguistically diverse kindergarten children this study examined response patterns of young
Canadian children using the Peabody Picture Vocabulary Test –Third Edition (PPVT-III, Dunn
& Dunn, 1997). Questions have been asked about whether the PPVT-III is an appropriate
measure to use with young English Language Learners (ELL) because items may be culturally or
linguistically biased. Further, it is of both psychometric and educational relevance to understand
measurement of English vocabulary acquisition among young English First Language (EL1) and
English Language Learner (ELL) children. PPVT-III scores were compared in two language
groups – 52 EL1 and 73 ELL 4- and 5-year-old children. There were significant differences
between the two groups in overall standard scores, with EL1 students performing significantly
better than ELL students. In contrast, demographic factors of grade, gender and maternal
education were not related to PPVT-III standard scores. A Mantel-Haenszel Differential Item
Functioning (DIF) analysis provided a detailed picture of how individual test items functioned
psychometrically in the two language groups. This analysis showed limited indications of DIF
in the first 168 items of the PPVT-III, suggesting minimal test bias on the PPVT-III. Further
analyses examined teachability of items, that is, how easily words can be taught, and the
semantic categories of items, that is, parts of speech such as verbs, nouns and adjectives. These
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further analyses showed that the mean proportion of correct scores for all types of words was
significantly different for EL1 and ELL children. Based on these detailed analyses it was
concluded that differences in PPVT-III standard scores for EL1 and ELL 4- and 5-year-old
children were not due to test bias, nor were they due to specific item properties. The mean
differences observed between EL1 and ELL children were thus taken to reflect item impact, a
difference in overall receptive vocabulary. In addition to establishing the utility of the PPVT-III
for linguistically diverse kindergarten children this study also provides a descriptive picture of
how EL1 and ELL children show variation across different types of word learning.
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Acknowledgements
My supervisor, Dr. Janette Pelletier, was a constant support throughout the entire process of my
PhD program. She offered continual motivation and support and was always available to answer
questions, read drafts and discuss important issues. Her immense knowledge and experience in
the field of early childhood research allowed this project to be so successful. I would also like to
thank my committee members, Dr. Carl Corter and Dr. Ruth Childs. Their expertise in research
methods, child development and educational measurement were an invaluable help. Without
them this project also would never have been completed. I would also like to acknowledge the
support of Dr. Olesya Falenchuk. She offered guidance and support throughout the analysis and
writing process.
I am grateful for the support of my family and friends. My husband, Aaron Platt,
provided unwavering support throughout this academic endeavor. He has supported this process
from the beginning and has pushed me to keep going when I felt the challenges were too great.
My son Avery has supported me with love and smiles. His presence kept me working and
looking towards my final goal. My parents, Margie and Jerome Shore, have inspired me with a
love of learning and the confidence that I can do whatever I put my mind to. Without their early
influence, none of this would have come to fruition.
I am also thankful to the children, families and schools who participated in the research.
Without them this important research would not have been possible. In addition, I am thankful
to the large research team who worked throughout the year to collect the data. This was an
extensive task carried out by a dedicated group of excellent researchers.
Finally, The Institute of Child Study is where I began my formal education and
completed my formal education. I am grateful to all of the people who have worked tirelessly
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over the years to maintain the vision of a child centered learning environment with research at
the core.
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Table of Contents
ABSTRACT II

ACKNOWLEDGEMENTS IV

TABLE OF CONTENTS VI

LIST OF TABLES VIII

LIST OF FIGURES IX

INTRODUCTION 1

LITERATURE REVIEW 9

Early Vocabulary Acquisition 9

Measuring Vocabulary 17

Differences in Children’s Performance on the PPVT-III in Relation to Demographic
Factors and Word Categorization 27

METHODS 45

Participants 45

Instruments 47

Procedure 50

RESULTS 60

PPVT-III total score analysis 60

Individual Item Analyses 64

Item Category Analyses 74

DISCUSSION 80

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Overview 80

Vocabulary Differences as a Function of Demographic Differences 80

Differential Item Functioning on the PPVT-III 84

Word Type Differences on the PPVT-III 86

The Appropriateness of the PPVT-III in a Canadian Multilingual Context 88

Implications 88

Limitations and Future Directions 91

Conclusions 92

REFERENCES 94

Appendix A 109

Appendix B 110

Appendix C 110


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List of Tables

Table 1 Means and Standard Deviations of PPVT-III Scores by Gender, Grade,
Language Status and Family Education 60
Table 2 Means and Standard Deviations for Groups of Students Defined by Grade,
Gender, Language Status and Maternal Education 61
Table 3 MH-DIF Statistics for Dichotomous Items 25 through 96 68
Table 4 Means and Standard Deviations Proportion Correct Scores by Teachability 77
Table 5 Means and Standard Deviations Proportion Correct Scores by Semantic
Category 77
Table 6 Paired Samples t-test Based on Teachability and Semantic Category 78

Table 7 Basic Nouns by Teachability Word Type 78

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List of Figures
Figure 1 Staircase Graph for ELL 65
Figure 2 Staircase Graph for EL1 66
Figure 3 Percentage of Correct and Incorrect Responses for EL1 and ELL children
on the PPVT-III 67
Figure 4 Teachability categorization of words per set on the PPVT-III 75
Figure 5 Semantic categorization of words per set on the PPVT-III 76

IX
Introduction
Early vocabulary acquisition plays an important role in the development of decoding
skills, reading comprehension and ultimate school success (Hart & Risley, 2003, 1995; National
Institute of Child Health and Human Development, 2000; Walker, Greenwood, Hart & Carta,
1994). Phonemic awareness, word identification and vocabulary are all considered instrumental
in developing competent reading skills that lead to successful reading comprehension
(Cunningham & Stanovich, 1997; National Institute of Child Health and Human Development,
2000). However, any of these three skills alone is not adequate for mature reading
comprehension; reading requires the combination of these three skills as well as oral
comprehension (National Institute of Child Health and Human Development, 2000). Research in
recent years has paid increasing attention to the positive roles that oral language development
and vocabulary acquisition play and the negative implications of low word knowledge for
reading comprehension (White, Graves & Slater, 1990).
In order to understand what is both heard and read, young children need to have a
well-developed receptive vocabulary, that is, the understanding of spoken words. However, there
are many challenges for young children in acquiring the meaning of a new word. A primary
challenge is the multiple meanings a single word may hold (Heibert & Kamil, 2005). In English,
multiple meanings of a single word are common and words are often used in different contexts,
thus creating a lexical challenge for children learning English. To make sense of new English
words, children must rely on the context in which they hear a word or on the pairing of a spoken
word with an object or action. A secondary challenge is discerning the meaning of a new word
from context when it is heard without an additional explanation, for example, “hare” and “hair”.
However, despite these two challenges it seems that children manage to learn the meanings of
1