One of the major obstacles when considering bilingual education starts with defining what actually constitutes bilingual education. Maria Brisk has defined bilingual education as the use of two languages as the media for instruction. However, within this broad definition lies a wide variety of approaches to bilingual education, especially in non-Western settings. For the purposes of this post I will focus mainly on English language learners in Thailand. (It should be noted that there are additional issues for speakers of minority dialects in Thailand - see, for example, Draper, 2012).
Within Thailand there are a number of approaches taken to bilingual education, although ways to describe these are not well defined. Broadly speaking there are two types of English Program in Thailand: Mini English Programs, where students receive 8-14 hours per week of English medium classes, and English Programs, where students receive at least 15 hours per week of English medium classes (Keyuravong, 2008, cited in Bax, 2010). My school falls into the latter category. In addition to English Programs there are bilingual schools, which have more variety in the number of hours devoted to English-medium teaching.
Advantages of bilingual education
In the past actual cognitive advantages of bilingual education were difficult to ascertain. In fact, at times the arguments around bilingual education tended to suggest there were cognitive disadvantages for learners. This argument has now shifted somewhat, with bilingual education no longer regarded as necessarily disadvantageous: 'Current studies that report no difference between groups present themselves as a challenge to claims of bilingual advantages rather than to claims of bilingual disadvantages...'
Further evidence for the cognitive benefits of bilingualism come from neurological studies, for example bilingual learners may have better information processing skills. In science this may help these learners get to grips with scientific language more quickly, because they already have the skills with which to assimilate a new language. These neurological studies also suggest that bilingualism affords neurological benefits that extend beyond the fact of their being bilingual, for example bilingualism being protective against neural decline in older age.
Other advantages that a bilingual education may confer are global competitiveness and global engagement. Being bilingual is highly likely to increase an individual's employment opportunities in today's globalized world. For example, the recent further integration of the ASEAN countries, of which Thailand is one, and that organization's adoption of English as its official working language, means that citizens of member states who are bilingual will have a competitive advantage. In addition, by pursuing a bilingual education, individuals may become more globally engaged, globally competent citizens. This could lead to them possibly becoming actively involved in human rights issues, or championing environmental issues, for example.
Disadvantages of bilingual education
If there are disadvantages to a bilingual education, these may be sociocultural rather than cognitive. Firstly, bilingual education may exacerbate social divisions, with only the wealthy elites able to access it, something that Hu (2008) argues is happening in China. Obviously, if only the wealthy can access bilingual education then this will have a negative impact on those learners who cannot. Secondly, bilingual education may privilege one language over a learner's first language, leading to a loss of cultural capital and a weakening of their first culture identity. This second disadvantage may then lead to poor learner outcomes by fostering a negative attitude to school and learning more generally.
Clearly, the disadvantages of bilingual education are important factors that should be taken into consideration, but are not in and of themselves arguments against bilingual education - rather they are an argument for a more egalitarian approach to the way societies and their education systems are structured. Taking these disadvantages into account then, I continue to feel that the benefits offered by bilingual education outweigh the negatives. I would be interested to hear others' views on this topic.