Proposing more ecologically-valid experiment protocol using YouTube platform.

Video streaming is becoming increasingly popular, and with platforms like YouTube, users do not watch the video passively but seek, pause, and read the comments. The popularity of video services is possible due to the development of compression and quality prediction algorithms. However, those algorithms are developed based on classic experiments, which are non-ecologically valid. Therefore, classic experiments do not mimic real user interaction. Further development of the quality and compression algorithms depends on the results coming from ecologically-valid experiments. Therefore, we aim to propose such experiments. Nevertheless, proposing a new experimental protocol is difficult, especially when there is no limitation on content selection and control of the video. The freedom makes data analysis more challenging. In this paper, we present an ecologically-valid experimental protocol in which the subject assessed the quality while freely using YouTube. To achieve this goal, we developed a Chrome extension that collects objective data and allows network manipulation. Our deep data analysis shows a correlation between MOS and objectively measured results such as resolution, which proves that the ecologically-valid test works. Moreover, we have shown significant differences between subjects, allowing for a more detailed understanding, of how the quality influences the interaction with the service.