This report, written by Fred Dobb and published by the California Science Project, identifies 10 elements crucial to good science instruction for ELLs: academic language through science instruction, affective factors, classroom talk, vocabulary development, the science textbook, science textbook teachers' guides, professional development, the Sheltered Science Instruction Observation Protocol, lesson study, and assessment. Dobb discusses each of these elements is in detail, with a particular eye toward providing practical information that teachers can use to support their ELLs' learning in the science classroom.
Dobb, Fred. (2004). Essential Elements of Effective Science Instruction for English Learners. 2nd edition. California Science Project: Los Angeles, CA. Retrieved from: http://docushare.ycs.k12.pa.us/docushare/dsweb/GetRendition/Document-7526/html.