Mislevy, J., Seftor, N., & Wei, X. (2021). IXL Math: Nonregulatory ESSA Standards Evidence Review & What Works Clearinghouse Standards Review. SRI.
IXL contracted with SRI Education for an independent review of a quasi-experimental study they conducted: “Assessing the Impact of IXL Math over Three Years: A Quasi-Experimental Study.” The study author conducted a retrospective analysis to investigate the extent to which school use of IXL Math during a three-year period was associated with higher rates of proficiency on statewide assessments. SRI determined that this study provides moderate evidence for IXL Math efficacy in grades 3-8 over a three-year period according to the ESSA levels of evidence provided by the U.S. Department of Education guidelines.