User Interface Design Strategies For Enhancing Website Use Convenience: An A/B Experimental Evaluation Based On Usability Metrics In E-Commerce Websites

Website use convenience is a critical determinant of user experience and performance in e-commerce. This study evaluates whether a bundle of user interface (UI) design strategies can improve convenience of use by comparing a baseline interface (Version A) with an optimized interface (Version B) using a usability-metrics–centered A/B experiment. Eighty participants were randomly assigned to Version A (n = 40) or Version B (n = 40) and completed five representative e-commerce tasks. Convenience was operationalized using ISO-aligned usability outcomes: effectiveness (task success), efficiency (time, clicks, errors), and satisfaction (System Usability Scale; SUS). Results showed that Version B significantly outperformed Version A in overall task success, t(78) = −2.96, p = .004, d = 0.66; reduced total completion time, t(78) = 5.17, p < .001, d = 1.16; reduced clicks, t(78) = 6.23, p < .001, d = 1.39; reduced errors, t(78) = 5.93, p < .001, d = 1.33; and increased SUS, t(78) = −4.48, p < .001, d = 1.00. Task-level analyses indicated the largest improvement for cart modification (Task 4), χ²(1) = 10.91, p < .001, φ = .37. Although shopping frequency differed between groups, robustness checks controlling for shopping frequency confirmed that group effects remained significant for total time and SUS (ps < .001). These findings support usability-metrics–driven UI optimization and demonstrate that A/B evaluation can yield strong, decision-relevant evidence for e-commerce interface redesign.