Video Quality of Experience in the Presence of Accessibility and Retainability Failures

Accurate Quality of Experience measurement for streaming video has become more crucial with the increase in demand for online video viewing. Quantifying video Quality of Experience is a challenging task. Significant efforts to quantify video Quality of Experience have primarily focused on the measurement of Quality of Experience for videos with network and compression related impairments. These impairments, however, may not always be the only main factors affecting Quality of Experience in an entire video viewing session. In this paper, we evaluate Quality of Experience for entire video viewing sessions, from the beginning to the end. In doing so, we evaluate videos with temporary interruptions as well as those with permanent interruptions or failures. We consider two types of failures, namely Accessibility and Retainability failures, and present the results of two subjective studies. These results indicate: (a) Accessibility and Retainability failures are rated lower compared to temporary interruption impairments; (b) Accessibility failures are rated close to the lowest value on the rating scale; and (c) the traditionally used 5-point scale to measure video Quality of Experience is not sufficient in the presence of Accessibility and Retainability failures.