As has been shown in Chapter 1, the classification of people into bilingual and monolingual groups is fraught with difficulty. It is too simplistic to place people into a monolingual or a bilingual group. We need to ask what language competences are being used for classification (Grosjean, 2012). Are all four basic language abilities being used? What is the degree of fluency in each language? Were bilinguals classified by their use of languages (functional bilingualism) or by their ability in language? As Chapter 1 revealed, who is or is not bilingual is a complex issue. The earlier research on bilingual ism and cognition tended to regard classification as non-problematic. This means that the research results are simplistic and ambiguous, having classified bilinguals in an imprecise manner.