The CALLA Handbook is an indispensable resource for all teachers who are responsible for teaching core curriculum subjects to language minority students in ESL or mainstream classrooms, at-risk students, and all students in bilingual and foreign language classrooms.
It took me a while to warm up to this book but in the end I loved it and strongly recommend it to anyone who teaches English Language Learners (ELLs) in pretty much any context. I think there's a lot in this book that's of value and can help you be a better teacher. I especially liked Chapters 9-12, which outlined CALLA for specific content areas.
I agree with the one reviewer who said that no single thing in here is "groundbreaking" per se -- however, looking at CALLA as a whole I think it is a fantastic way to teach ELLs. If you actually implement almost every aspect of this program then I think it can really be groundbreaking in the sense that you'll actually make learning meaningful and comprehensible to kids who don't have the language skills to "get" grade-level content. No other program that I know of focuses on the teaching learning strategies which I do think are incredibly helpful and need to be taught explicitly. As a former ELL myself, I am able to reflect on the ways that I did/didn't learn and I think a lot of what CALLA focuses on could be particularly helpful for this population.
Meant to assist teachers dealing with second language learners. None of the suggestions featured here are particularly helpful or ground-breaking. I firmly believe intuition trumps most of the formulated strategies presented here.