Further complicating issues related to oral language development and literacy acquisition are situations in which a student's first language is not shared by other students in his or her grade, the student's first is a language without adequate print sources for instruction, or the student cannot receive instruction because a bilingual education teacher is not available to provide it. For these reasons and myriad others, there are no formulas or ready guidelines that can be easily provided for assessment and treatment.

It is also noteworthy that although there are many caveats and considerations involved in decision making about screening, assessment, and intervention for ELLs, parents and educators cannot postpone decision making until a better knowledge base is available.