See the evidence
The research is clear: IXL is boosting achievement for 12 million students, including at schools near you.
IXL is proven to accelerate learning
In studies of schools in 34 states, results consistently showed that schools using IXL outperform schools using any other product or method. Additional third party research has also demonstrated the positive impact of IXL on a variety of student populations.
The efficacy studies examined data from state assessments for 66,790 public schools across these states. Schools in the studies varied in their usage of IXL and methods of implementation.
Schools using IXL outperformed schools not using IXL on the Standards of Learning (SOL) tests, by 5 percentile points in math and ELA, and this positive effect was even higher in low-income schools and rural schools.
Schools that discontinued IXL usage showed a performance drop on the SOL math and reading tests, by as much as 7 percentile points.
Impact of IXL in a VA school district
Students performed better on the SOL when they reached proficiency in more IXL skills per week (SP/week): One additional math SP/week is expected to increase students’ SOL Math scores by 18 points, and one additional ELA SP/week leads to an expected increase of 9 points on SOL ELA.
The IXL Diagnostic was a strong predictor of students’ SOL scores, and is thus a robust baseline assessment measure.
Grade-Level Predictive Validity of the IXL Diagnostic
Using the Virginia SOL as a criterion measure, this study found that the IXL Diagnostic is a reliable and valid measure of student grade-level proficiency in both math and ELA.
Specifically, between IXL Diagnostic and SOL there is a strong correlation in scores (>.70) and a high degree of overlap in student proficiency classifications, and IXL’s Diagnostic also showed high test-retest reliability.
Predictive validity of IXL's Diagnostic Among Marginalized Students
IXL's Diagnostic was found to be a good predictor of subsequent academic performance as measured by MAP Growth, with a correlation of .85 in math and .82 in ELA.
This finding also held true among ELL, special education, and economically disadvantaged students.
IXL Design Principles
IXL’s product is grounded in research and best practices. This white paper highlights the design principles used in its development with special emphasis on the strong connection between learning science research and core features of the IXL experience.
Impact of IXL in 7 States
IXL schools in Illinois, Louisiana, Nebraska, New York, South Carolina, Tennessee, and Washington outperformed non-IXL schools in both math and language arts.
Among IXL schools, more IXL usage is associated with higher achievement.
IXL schools across 10 states outperformed the others by 4 percentile points on the Smarter Balanced Assessments for math and English language arts.
Low-income schools and schools with high numbers of English language learners made even greater gains on their standardized assessments.
IXL Math and ELA Efficacy: ESSA Research Report
Students using IXL experience significantly greater growth on the NWEA MAP assessments for math and ELA than students without IXL.
With this study, IXL Math and IXL ELA meet the criteria for Tier II evidence-based interventions set by the U.S. Department of Education's Every Student Succeeds Act (ESSA).
Predictive validity of IXL’s Real-Time Diagnostic
This study proved the predictive validity of the Real-Time Diagnostic, finding strong positive correlations between the Real-Time Diagnostic and the NWEA MAP Growth math and reading assessments.
Additionally, for both subjects, students whose Real-Time Diagnostic scores were on or above grade level were more likely to have MAP scores equal to or above MAP norm levels.
Construct and Predictive Validity of IXL’s Real-Time Diagnostic
Researchers found that the IXL Real-Time Diagnostic demonstrates high reliability as a measure of math and ELA achievement.
Additionally, IXL's diagnostic is a good predictor of performance (using ILEARN as a criterion measure), with a correlation of .90 in math and .86 in ELA.
The Effect of IXL on ELL and SpEd students
Students using IXL performed better on the ILEARN math assessment when they used IXL more (e.g. answered more questions, reached proficiency in more skills, mastered more skills, etc.)
Both English language learners and special education students experienced similar or even greater gains in performance with additional usage of IXL.
Impact of IXL Professional Development Programs
Schools that participated in IXL Professional Development programs showed a significant increase in student engagement with IXL.
Those schools also had higher proficiency rates on the Illinois state assessments for both math and ELA, compared to IXL schools that did not participate in IXL PD.
IXL schools performed better than non-IXL schools on both the math and ELA sections of the California Assessment of Student Performance and Progress (CAASPP).
The expected number of students with proficient scores on the CAASPP would increase by 8.5% for math and 10% for ELA if students mastered one additional IXL skill per week.
Improving Outcomes in a Before-School Math Lab
IXL boosted scores on the math section of the California Standardized Test (CST) in a Title I elementary school by 23 points.
After the school stopped using IXL, the school saw a 24 point drop on 4th grade CST scores in math.
IXL's Impact on California Dashboard Rating
California schools using IXL have a higher probability of achieving the most desirable ratings (Blue and Green) on the California Dashboard for both math and ELA.
Over a three-year period, IXL schools outperform non-IXL schools by 8% on the Dashboard for math and 10% on the Dashboard for ELA.
The proficiency rate on the PARCC in schools using IXL for one year was 5 percentile points higher in math and 4 percentile points higher in ELA compared to schools not using IXL.
Schools using IXL for two years had a PARCC proficiency rate 9 percentile points higher in math and 8 percentile points higher in ELA compared to non-IXL schools.
Texas schools using IXL outperformed schools without IXL on STAAR exams, by as much as 11 percentile points on math, 17 percentile points on reading, and 8 percentile points on writing.
Schools using both IXL Math and ELA received better accountability ratings from the Texas Education Agency (i.e., showed higher achievement, made more progress, and closed achievement gaps better) than similar schools using just one IXL subject.
Schools using IXL for at least one year had an ELA passing rate 7 percentile points higher on the Florida State Assessment (FSA) compared to schools not using IXL.
In schools using IXL for two years, the math passing rate on the FSA was 15 percentile points higher in schools compared to non-IXL schools.
New York schools using IXL outperformed schools without IXL on the New York State Testing Program (NYSTP) and Regents Exams.
In 2013, schools using IXL for at least 3 years outperformed non-IXL schools by 13 points on the math Performance Index (PI).
By 2014, the PI gap between the same schools grew to 15 points. In 2015, the PI gap jumped to 18 points.
Thirty-two percent of schools using two IXL subjects and 30 percent of schools with one IXL subject improved their school performance grades on the North Carolina EOG and EOC exams, compared to just 18 percent of non-IXL schools.
Schools using IXL Math for three school years demonstrated increasing gains over time, growing by 3 percentile points in the first year to a growth of 7 percentile points in the third year.
Indiana schools using IXL outperformed schools without IXL in both math (5 percentile points) and ELA (6 percentile points) on the Indiana Statewide Testing for Educational Progress-Plus (ISTEP+).
The positive impact of IXL was even greater in low-income schools and urban schools.
Schools that used IXL for one year outperformed schools without IXL by 7 percentile points in ELA and 3 percentile points in math on the Georgia Milestones Assessment System (Georgia Milestones).
Schools that used IXL for two years demonstrated even higher gains, outperforming non-IXL schools by 16 percentile points in ELA and 6 percentile points in math.
Schools using IXL outperformed schools not using IXL on PARCC, by 4 percentile points in math and 6 percentile points in ELA.
The expected percent proficient on PARCC would increase 12% for math and 4% for ELA if students mastered one additional IXL skill per week.
On the Minnesota Comprehensive Assessments (MCA), the proficiency rate for Title I schools using IXL was 8 percentile points higher in math and 13 percentile points higher in ELA compared to Title I schools not using IXL.
Minnesota schools with at least 30% ELLs using IXL had a proficiency rate 7 percentile points higher in math and 12 points higher in ELA compared to high-ELL schools not using IXL.
Hawaii schools using IXL Math outperformed schools not using IXL by 6 percentile points on the Smarter Balanced Assessments (SBA).
The positive effect of IXL Math was even higher for low-performing schools (8 percentile points) and for schools located in towns or rural areas (12 percentile points).
Elementary and middle schools using IXL outperformed schools not using IXL on the M-STEP for math and ELA.
Schools using both IXL Math and IXL ELA also received better accountability ratings in the Michigan School Index System (i.e., higher overall index value, proficiency index value, and growth index value).
Massachusetts schools using IXL outperformed schools with IXL on the Next-Gen MCAS for math and English language arts.
The IXL effect was even greater in schools in urban areas and low-performing schools.
Impact of IXL Science in a Massachusetts School District
Students who practiced more on IXL Science performed better on the MCAS-Science and Technology/Engineering exam, by as much as 16 percentile points.
Specifically, when students spent more time, answered more questions, practiced more skills, and/or reached proficiency or mastery on more skills, they scored higher than students with lower usage of IXL.
Schools using IXL improved their performance on the PSSA and Keystone Exams for math and English language arts compared to schools not using IXL.
In addition, analysis showed that if students mastered just one more IXL skill per week, their school would increase their proficiency rate by 13 points in math and 15 points in ELA.
Oklahoma Statewide Efficacy
Oklahoma schools that used IXL outperformed schools that did not use IXL on state STEM assessments (5 percentile points on OSTP Math and 11 percentile points on OSTP Science).
Schools using both IXL Math and IXL Science were 3.25 times more likely than non-IXL schools to receive an overall school letter grade of A or B.
IXL schools outperformed schools without IXL on Ohio's State Tests and the longer they used IXL, the more growth they experienced.
Schools using IXL were more likely to receive an overall school grade of A or B on the Ohio School Report Card than schools without IXL.
Students Show Greater Growth on MAP Test with IXL
After practicing on IXL Math for one school year, 5th grade students in Iowa demonstrated larger gains on the NWEA MAP test, with 65% of IXL students exceeding normative growth, compared to only 41% of students who did not use IXL.
English language learners and students in special education programs made the most improvement compared to students without access to IXL.
IXL Improves Math Skills in Title I School
With the support of IXL Math and intervention groups, 4th grade students in a Title I school in Washington outperformed their peers and exceeded the district average on the Smarter Balanced assessment (SBA).
88 percent of students who used IXL met or exceeded grade-level standards compared to only 49 percent of students from the other Title I elementary schools in the same district.
IXL Drives Student Achievement in Math
IXL's effect on the Oregon Assessment of Knowledge and Skills (OAKS) math test scores is equivalent to 6.2 weeks of extra instructional time each year, according to results from a study conducted in an Oregon school district.
100 percent of teachers surveyed said that their students' confidence in learning math increased.
IXL for RTI Leads to School Turnaround
By incorporating IXL into their Response to Intervention (RTI) strategy, a rural high school in Kentucky skyrocketed from below the 5th percentile in state rankings to a 97th percentile state ranking in just two years.
By the second year, 30 percent of the high school Individualized Education Plan (IEP) students passed the state end-of-course assessment for Algebra I, compared to 15 percent statewide.
Kentucky Statewide Efficacy
Kentucky schools that used IXL Math or IXL ELA outperformed schools that did not use IXL on K-PREP.
The longer the schools used IXL, the better they performed: schools that used IXL for 3 years ranked 13 percentile points higher in math and 15 percentile points higher in ELA than non-IXL schools.
The Effect of IXL in an Indiana School District
Students using IXL performed better on the ILEARN in both math and ELA when they used IXL more (e.g. answered more questions, reached proficiency in more skills, mastered more skills, etc.)
Economically disadvantaged students experienced similar or even greater gains in performance with additional usage of IXL.
Schools using IXL STEM products (IXL Math and/or IXL Science) outperformed non-IXL schools on the corresponding Scantron assessment (8 percentile points in math and 4 percentile points in science).
Schools that used IXL Math and/or IXL Science were also 1.79 times more likely to receive letter grades of A or B than schools that did not use IXL.
Colorado State Efficacy
IXL schools outperformed non-IXL schools on the Colorado Measures of Academic Success (CMAS) assessments, by 6 percentile points in math and 4 percentile points in language arts, over a one-year period.
Missouri Statewide Efficacy
Schools that used IXL outperformed non-IXL schools on the Missouri Assessment Program (MAP) in both math (5 percentile points) and ELA (6 percentile points). Schools with a high percentage of special education students experienced similar or even larger effects.
More time spent on IXL Math, more questions answered, and more skills proficient were all positively related to a higher school proficiency rate in math on MAP.
Kansas State Efficacy
Schools that used IXL performed better on the Kansas Assessment Program (KAP) than comparable schools that did not use IXL.
Higher IXL usage was also associated with better performance. Students reaching proficiency in one additional IXL Math or ELA skill per week is expected to increase schools’ KAP Math and ELA proficiency rates by 3 percentage points and 5 percentage points, respectively.
Iowa State Efficacy
Students who used IXL performed better on the Iowa Statewide Assessment of Student Progress (ISASP).
The proficiency rate among students who used IXL ELA was 4 points higher on the ELA portion of the assessment compared to non-IXL students, which translates to a 15 point gain in percentile rank.