A Psychometric Evaluation Framework for Mobile Ux: Developing a Validated Questionnaire for Assessing Cognitive Load in Elderly Smartphone Users

Abstract

The rapid proliferation of smartphone technology has created significant usability challenges for elderly users, particularly regarding cognitive load management during mobile interactions. This study presents the development and psychometric validation of the Elderly Smartphone Cognitive Load Questionnaire (ESCLQ), a novel instrument designed to assess cognitive workload in mobile user experience contexts for older adults aged 60 and above. Drawing upon established cognitive load theory, the NASA Task Load Index framework, and age-specific mobile usability principles, we developed a 24-item questionnaire across four dimensions: perceptual processing, motor-cognitive coordination, navigation complexity, and emotional-cognitive strain. The validation process involved 312 elderly participants (mean age = 68.4 years, SD = 6.2) across two phases: exploratory (n=156) and confirmatory (n=156). Exploratory factor analysis revealed a stable four-factor structure explaining 71.3% of the total variance, while confirmatory factor analysis demonstrated excellent model fit indices (CFI = 0.94, TLI = 0.93, RMSEA = 0.06). The ESCLQ demonstrated high internal consistency (Cronbach's α = 0.89) and strong test-retest reliability (ICC = 0.85) over a two-week interval. Convergent validity was established through significant correlations with the System Usability Scale (r = -0.67, p < 0.001) and NASA-TLX (r = 0.72, p < 0.001). Discriminant validity analyses confirmed the questionnaire's ability to differentiate between varying levels of interface complexity and user expertise. This validated instrument provides researchers and practitioners with a reliable, psychometrically sound tool for evaluating cognitive load in elderly smartphone users, facilitating the development of age-appropriate mobile interfaces and contributing to digital inclusion efforts for aging populations.