Operationalizing and measuring language dominance

Abstract
The aim of this article is to show how measures of lexical richness (Guiraud, 1954; Malvern, Richards, Chipere, & Durán, 2004) can be used to operationalize and measure language dominance among bilinguals. A typology of bilinguals is proposed based on these measures of lexical richness, and the validity of the typology is then investigated in an empirical study among two groups of bilingual informants with different language dominance profiles (25 Dutch—French bilinguals from Brussels and 24 French—English bilinguals from Paris). The most important advantage of the proposed operationalization is that it allows researchers carry out precise measurements of bilingual ability in languages or language varieties for which no standardized tests exist and that these measures can be calculated on oral data that have been collected in an informal and unobtrusive way, in a naturalistic setting.