In addition to questions of language proficiency, class schedules and grouping practices had to be changed in order to create some classrooms that were to be taught bilingually while others were not. However, the changes required in subtractive programs were fewer and less demanding than those that were required in programs of additive bilingual education, in which both languages are taught for an extended period and literacy in two languages is the goal for all students. non dual teaching
Further, in many of these programs, native-English-speaking children were to be involved alongside classmates who were English language learners. In such cases, programs required even greater planning and accommodation of divergent needs, such as when and for how long the two groups should interact to help each other learn their respective languages. The underlying assumptions and values of additive bilingual education, now often referred to as dual-language programs or two-way immersion, are substantially different from the underlying notions of subtractive programs.
Additive bilingual education is grounded in the ideas (a) that all children can and should learn more than one language as part of a liberal education, (b) that the underlying principles of multicultural education extend to language diversity, and (c) that children who already speak a home language other than English should be given opportunities to continue the formal study of that language and achieve literacy in it. Remediation and compensating for prior experiences are not used as criteria to include or exclude children from these programs.
Instead of assuming that the home language is a barrier to learning English, it is seen as a communications tool that should be used and further developed because it facilitates learning. The view of language diversity underlying programs of additive bilingual education is very different from the views of language differences on which subtractive programs are based. First, in an additive (dual language) program, both languages are afforded the same deference, respect, and recognition in every aspect of the school.
Teachers, except those whose jobs are to teach English or non-language-related courses, such as physical education, art, or music, must be bilingual and to some important degree biliterate. This is perhaps the major obstacle to the creation of dual language programs today in almost every part of the country. Many people in the United States today are literate in languages other than English, but they have not been trained as teachers and must be retrained and certificated by the appropriate agency of the state if they are to take on that role effectively.
Regrettably, most colleges and universities that train teachers for bilingual education do so under the assumption that such teachers will work in programs of a subtractive nature simply because they are the most numerous and more politically acceptable to funding agencies. Most additive programs of bilingual education today have a strong parental involvement component, because parental choice and support are absolute requirements.
In some schools of this type, parents are asked to sign a formal agreement with the school in which they agree to actively participate in school affairs.