Distortions in QoE assessment of 3D multimedia services on multi-access mobile devices

Continuous monitoring of performance is a necessary tool for the maintenance and improvement of service quality. This applies to the rapidly developing 3D multimedia applications, where acceptability and user experience are the ultimate determinants of value. Satisfying demands in order to achieve high level Quality of Experience is challenging due to Quality of Service requirements and sensitivity of 3D services, especially in case of multi-access devices capable to benefit from wired, wireless and mobile network technologies. Feedback procedures relying on human evaluators are considered to be one of the most important industrial inputs of QoE monitoring. Distortions regarding this input necessitate additional attention due to their ability of making measurement results considerably inaccurate and misleading. This paper aims to observe and analyze the effect of specific environmental information, which is commonly public to the evaluators. The performed series of measurements demonstrates how the awareness of the type of connection can make constant objective quality to result in a rather varying subjective quality. It is also revealed how cognitive dissonance played a role during the evaluation of streaming services on a portable 3D terminal. In order to support understanding evaluator behavior, measurement subjects were distinguished by Level of Comprehension, based on prior technical knowledge and experience.