In the debate over bilingual education, one devilishly simple question keeps coming up: Does it work?
That may be easier asked than answered.
Hundreds of studies have tried to assess bilingual education’s effectiveness in the three decades since native-language instruction became widely used in U.S. schools.
Most found bilingual teaching methods effective, says Stephen Krashen, a University of Southern California education professor who favors bilingual education.
Most of the valid ones gave the edge to other methods, counters Christine Rossell, a Boston University political scientist who backs an anti-bilingual ballot proposal in Massachusetts.
But these studies looked at only a few grade levels – how kindergartners fared by fifth grade, for example. No researcher ever did the one project that might settle the matter: a long-term study showing how large numbers of English learners who were schooled with bilingual methods compare – as adults – with peers who used other methods.