Study on user quitting rate for adaptive bitrate video streaming

Abstract

In this study, the effect of coding degradation and stalling events on the percentage of users who quit watching videos midway is studied (referred to as the user quitting rate). The results are based on three laboratory-based subjective experiments involving up to 104 participants. The results show that for the coding condition only, a Mean Opinion Score (MOS) lower than 3 on a 5-point ACR quality scale will result in users quitting the video. The quitting rate was found to increase further when the MOS falls below 2.5. When a stalling event occurs, the quitting rate was found to be dependent on the stalling position, the stalling duration, the percentage of user who already quit, and the MOS. Statistical analysis allowed the identification of interaction terms between the stalling position and percentage of users who had already quit. Finally, the results were used to establish a model of the user quitting rate due to stalling.