Visual Complexity and Feedback Modality in In-Flight Entertainment Inter-faces: An Experimental Study of Duration Estimation and Usability

Visual complexity and feedback modality may influence perceived interaction duration, yet their effects on subjective and objective task outcomes remain unclear. This study examined duration estimation and usability in in-flight entertainment (IFE) interfaces. In a 3 × 3 mixed-factorial experiment, 63 participants completed six tasks in a simulated aircraft cabin. Visual complexity (low, medium, high) was manipulated between participants, whereas feedback modality (none, visual-only, visual–auditory) varied within participants. Higher visual complexity increased subjective duration estimates compared with low complexity, while actual completion time did not differ significantly. Visual–auditory feedback produced greater duration underestimation than no feedback or visual-only feedback. Feedback modality also significantly affected perceived system usability. Visual complexity and feedback modality interacted on ease of use, but not on the primary time measures. A supplementary eye-tracking study with 22 additional participants indicated descriptive differences in gaze distributions, although quantitative eye-movement metrics did not differ significantly across complexity levels. These findings suggest that visual information organization and confirmation feedback influence subjective duration judgments and usability in different ways, informing the human factors evaluation of task-oriented interfaces.