There are a number of considerations when assessing ELL students. The first consideration is the number of and type of tasks required by the assessment. Another consideration is scaffolding which allows the ELL to demonstrate their knowledge in various ways and through various types of assessment. In addition, grading is important in terms of the weight of the task assigned. Most importantly, providing clear expectations is essential when assessing EL students.
https://www.coursera.org/lecture/ell-assessment/considerations-for-assessment-creation-gFxj7
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