ABSTRACT
This chapter examines important concepts and ideas from the language sciences that are critical to properly addressing language issues in the assessment of ELL students. It provides four sections: Language as a System, Assessment as a Communication Process, Understanding English Language Learners, and Language Variation. Language as a System provides a functional perspective according to which languages are systems of conventions. Assessment as a Communication Process provides a conceptual perspective according to which testing and classroom assessment activities involve social interaction through language. Understanding English Language Learners discusses how these students' linguistic skills are commonly under appreciated. Language Variation discusses how individuals and groups vary in the ways in which they use the same language. Facets of this variation include the diversity of dialects in the same language, diverse forms of specialized language such as academic language, and code-switching.
