What is the best method for assessing ELLs' growth in both their first language (L1) and second language (L2)?

Utilizing assessments that include portfolios demonstrating performance over time is the best method for assessing ELLs' growth in both their first language and second language. Portfolios provide a comprehensive picture of a student's progress by compiling a variety of work samples, such as written assignments, projects, and recordings, over an extended period. This method allows educators to analyze improvements, understand individual learning trajectories, and assess both languages in a contextualized manner.

Portfolios encourage reflection and self-assessment from the students, engaging them in the learning process. They can showcase a range of skills and competencies across their first and second languages, providing insights that standardized tests may not capture. This holistic approach is particularly effective for ELLs, who may demonstrate different strengths and challenges in their language learning journeys.