Instrument adaptation for measuring early child language development across multilingual and sociocultural diverse settings.

Abstract

This article describes the adaptation of the MacArthur-Bates Communicative Development Inventory (CDI) for South Africa's 11 official spoken languages. The CDI is a parent-report tool that measures early language development from 8 to 30 months. We developed cross-linguistically comparable CDIs, representing two distinct language families, West Germanic and southern Bantu, using a common protocol. We describe our approach to item construction and harmonization across languages and to obtaining sociodemographic information in different cultural settings. Issues such as language contact and variation, sampling, data collection, and quality control are discussed as well as item selection and instrument reliability and validity. This study highlights key issues for CDI adaptations and other instrument development in understudied contexts and discusses the theoretical implications of adding this diverse set of cross-linguistically comparable languages for early child language research. (PsycInfo Database Record (c) 2026 APA, all rights reserved).