Commercial age-friendly modes are increasingly embedded in smartphone applications, yet their task-performance implications for older adults remain uncertain. This two-stage study used a cognitively informed ecological-to-controlled strategy linking evaluation of commercial age-friendly versions with controlled testing of specified interface components while modeling older adults’ task-relevant cognitive ability. In Experiment 1 (n = 22), older adults completed ten tasks in standard and age-friendly versions of WeChat and Pinduoduo. The age-friendly versions showed no overall advantage in clicks, completion time, or erroneous clicks (all ps ≥ 0.548). Activity Theory-informed video coding identified recurrent task-to-interface mismatches, including insufficiently salient feedback. The exploratory Task 8 product-search observations, together with these coded interaction problems, indicated that product search was a relevant context in which menu configuration, action confirmation, and cognitive demands could be examined together. Because the commercial app versions differed across content and interface features, Experiment 2 (n = 30) used a custom Android product-search task to manipulate menu configuration and vibration feedback while modeling delayed recall continuously as an indicator of task-relevant cognitive ability. Relative to the flat configuration, the two-level menu was associated with 56.7% fewer clicks and 30.7% shorter completion time, whereas vibration feedback was associated with 20.2% fewer ineffective clicks. Delayed recall was associated with completion time in the primary model, but this association was attenuated after adjustment for age and sex. Together, the findings show that a commercial age-friendly label should not be treated as evidence of performance benefit. By separating ecological diagnosis from controlled component testing, the study provides an evidence pathway for translating real-world human–computer interaction problems into testable, task-specific interface components and supports a cognitively informed, information-structure-prioritized, and multisensory approach to smartphone-based product-search design for older adults.
Hu et al. (Fri,) studied this question.