2026 ASEE Annual Conference & Exposition

Spatial visualization skills are critical prerequisites for success in engineering, yet the wide variance in student baseline abilities poses a significant challenge to traditional instructional methods. This paper investigates the effectiveness of an iterative, online practice model designed to foster spatial proficiency through mastery learning. Conducted over a six-year period (2019–2025) with Georgia State University’s engineering students, the study utilized a structured framework consisting of paired pre- and post-assessments and a series of three iterative online workbooks. Unlike time-limited assessments, the workbooks prioritized deliberate practice by allowing unlimited attempts. Statistical analysis using paired t-tests revealed a highly significant improvement in spatial proficiency (p < 0.001), with post-test scores increasing despite a 50% reduction in testing time, indicating enhanced cognitive fluency. Cluster analysis identified three distinct learning trajectories: High-Efficiency learners, Persistent Improvers, and a High-Effort/Low-Gain group. Notably, while the model proved resilient during the COVID-19 pandemic's shift to remote learning, the discovery of a "practice plateau" among high-effort learners suggests that quantitative repetition alone does not guarantee mastery for all students. The findings also emphasize that cumulative assessment performance is a stronger predictor of terminal success (r = 0.82) than total engagement time.