Predictive Validity of the IXL Flex Diagnostic Using the ACT

This research report assesses the predictive validity of the IXL Flex Diagnostic by using the ACT as a criterion measure. The study analyzes the correlation between students' scores on the IXL Flex Diagnostic and their performance on the ACT in math, reading, and English language arts (ELA) for students in grades 9 through 11. The report presents findings that indicate strong positive correlations between the IXL Flex Diagnostic scores and ACT scores across all subjects. Additionally, it discusses the alignment of student proficiency classifications between the two assessments, revealing a significant overlap in how students are classified in terms of meeting or not meeting expectations. The study utilizes data from IXL's database, including ACT scores and IXL Flex Diagnostic scores, to provide a robust analysis of the assessment's validity. The results contribute to the understanding of the IXL Flex Diagnostic's effectiveness in measuring academic proficiency and readiness for college-level work.