The common underlying proficiency (CUP)
￼The term common underlying proficiency (CUP) has also been used to refer to the cognitive/academic proficiency that underlies academic performance in both languages(Cummins 2000: p. 38),
Consider the following research data that support this principle:
• In virtually every bilingual program that has ever been evaluated, whether intended for linguistic majority or minority students, spending instructional time teaching through the minority language entails no academic costs for students' academic development in the majority language (Baker, 1996; Cummins & Corson, 1997).
• An impressive number of research studies have documented a moderately strong correlation between bilingual students' LI and L2 literacy skills in situations where students have the opportunity to develop literacy in both languages. It is worth noting that these findings also apply to the relationships among very dissimilar languages in addition to languages that are more closely related, although the strength of relationship is often reduced (e.g. Arabic-French, Dutch-Turkish, Japanese-English, Chinese-English, Basque- Spanish) (Cummins, 1991c; Cummins et al., 1984; Genesee, 1979; Sierra & Olaziregi, 1991; Verhoeven & Aarts, 1998; Wagner, 1998).
• A comprehensive review of US research on cognitive reading processes among ELL students concluded that this research consistently supported the common underlying proficiency model:
• United States ESL readers used knowledge of their native language as they read in English.
• Native-language development can enhance ESL reading. (Fitzgerald, 1995:181)
Within a bilingual program, instructional time can be focused on developing students' literacy skills in their primary language without adverse effects on the development of their literacy skills in English.
• The relationship between first and second language literacy skills suggests that effective development of primary language literacy skills can provide a conceptual foundation for long-term growth in English literacy skills. This does not imply, however, that transfer of literacy and academic language knowledge will happen automatically; there is usually a need for formal instruction in the target language to benefit a cross-linguistic transfer.