Performance of a receptive language test among young children in Madagascar.

Ann M Weber,Emanuela Galasso,Lia C H Fernald,Lisy Ratsifandrihamanana,Jakob Pietschnig

doi:10.1371/journal.pone.0121767

Ann M Weber, Emanuela Galasso + Show 3 more

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https://doi.org/10.1371/journal.pone.0121767

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Abstract

Language tests developed and validated in one country may lose their desired properties when translated for use in another, possibly resulting in misleading estimates of ability. Using Item Response Theory (IRT) methodology, we assess the performance of a test of receptive vocabulary, the U.S.-validated Peabody Picture Vocabulary Test-Third Edition (PPVT-III), when translated, adapted, and administered to children 3 to 10 years of age in Madagascar (N = 1372), in the local language (Malagasy). Though Malagasy is considered a single language, there are numerous dialects spoken in Madagascar. Our findings were that test scores were positively correlated with age and indicators of socio-economic status. However, over half (57/96) of items evidenced unexpected response variation and/or bias by local dialect spoken. We also encountered measurement error and reduced differentiation among person abilities when we used the publishers’ recommended stopping rules, largely because we lost the original item ordering by difficulty when we translated test items into Malagasy. Our results suggest that bias and testing inefficiency introduced from the translation of the PPVT can be significantly reduced with the use of methods based on IRT at both the pre-testing and analysis stages. We explore and discuss implications for cross-cultural comparisons of internationally recognized tests, such as the PPVT.

Highlights

Interventions worldwide aim to improve developmental outcomes for young children [1, 2], generally targeting the negative correlates of poverty such as inadequate nutrition, health care, or education
We demonstrate in this paper that it is difficult to obtain an unbiased estimate of language ability in children from cultures that differ from where such tests were normed
Research in early language development is occurring across cultures and countries [19], and the need already exists for tools that allow for making valid international comparisons [48]

Summary

Introduction

Interventions worldwide aim to improve developmental outcomes for young children [1, 2], generally targeting the negative correlates of poverty such as inadequate nutrition, health care, or education. Child assessments used to examine the effectiveness of these interventions often focus on the language domain, since successful language skills are crucial to cognitive and socio-emotional development [3]. Early language skills predict later cognitive function among children in both high-income [4, 5] and low-income countries [6, 7]. Language ability may be responsive to early intervention because it is a higher cognitive process that does not achieve adult levels of development until late in adolescence [8]. As children enter their preschool years, their knowledge and use of language can be measured directly.

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