Spaced Learning Supports Productive Struggle in an Online Learning Platform

The goal of this study was to investigate how two well-established learning science principles—spaced learning and productive struggle—interact to benefit learning on a widely-used educational technology platform (IXL). When students use IXL, they complete practice problems organized within skills, or specific topic areas within a subject. We obtained IXL skill practice data in math and English language arts from 9,216 K-5 students in one Midwestern school district. We then classified students’ practice on each skill as (1) massed or spaced, and (2) low-struggle or high-struggle. We hypothesized that spacing skill practice would have a smaller impact on learning in low-struggle IXL skills (i.e., skills in which students made few errors), whereas spacing would have a larger impact on learning in high-struggle (i.e., challenging) IXL skills. Using multilevel models to analyze student practice of over 11,000 IXL skills, we found that spaced practice was more beneficial than massed practice (ps < .001). Key to our hypothesis, we found a significant interaction between learning schedule and productive struggle, such that the spacing effect was largest for high-struggle skills (ps < .001). These results provide large-scale evidence in a real-world educational setting that productive struggle supports student learning and that spaced learning can further enhance the positive effects of productive struggle. Practically speaking, these findings suggest that educators can benefit from using e-learning tools that incorporate spaced learning as one strategy to support students’ productive struggle, which in turn can boost academic growth.