Academic growth trajectories of ELLs in NAEP data: The case of fourth- and eighth-grade ELLs and non-ELLs on mathematics and reading tests

Utilizing the National Assessment of Educational Progress (NAEP) data, this study examined (1) how fourth and eighth-grade ELLs' mathematics and reading scores on national tests compared to their non-ELL peers' scores over the testing period between 2003 and 2011, and (2) if gender and ethnicity contributed to variation in the growth patterns among the student groups across grade levels and content areas. Since the NAEP data, which provides a national sample of 10,000–20,000 students, is collected using a probability sample design, sampling weights are adjusted so inferences can be appropriately made. Sample sizes within NAEP are large enough to generate adequate power for statistical significance. Thus, to display the data in a multivariate mode, Tableau 8.0.0 software was used. Results suggested that the achievement gap between non-ELLs and ELLs is either steady or slightly widening in both mathematics and reading, with multiple paths across the content areas, grade levels, and gender and ethnic groups.