Investigating Task Efficiency and User Satisfaction in Dynamic Conditions through In-Car Interactions

This study investigates the adaptability of three interaction modali-ties—touch screens, physical buttons, and voice commands—within in-car envi-ronments subjected to varying lighting (normal, overly bright) and noise (quiet, noisy) conditions. The objective is to understand how these environmental factors influence task efficiency and user satisfaction, with implications for designing robust multimodal systems. A mixed-design experiment was conducted, where 20 participants completed two tasks—music playback (short task) and navigation setup (long task)—using the three modalities across four environmental condi-tions. Task completion times and user satisfaction ratings were collected and ana-lyzed to evaluate the impact of environmental factors. The results indicate that voice interaction performs well in quiet environments, particularly excelling in long tasks. However, its performance declines significantly in noisy conditions due to recognition errors. Touch screen interaction shows strong performance under normal lighting but is adversely affected by overly bright environments, reducing visibility and satisfaction. Physical button interaction demonstrated the most con-sistent performance and satisfaction across all conditions, making it particularly suitable for high-frequency or urgent tasks. These findings provide empirical evi-dence supporting the development of adaptive strategies to enhance usability and satisfaction in dynamic environments.