Video Stream Quality Impacts Viewer Behavior: Inferring Causality Using Quasi-Experimental Designs
Video Stream Quality Impacts Viewer Behavior: Inferring Causality Using Quasi-Experimental Designs
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DOI：
10.1109/tnet.2013.2281542
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发表时间：
2013-12-01
影响因子：
3.7
通讯作者：
Sitaraman, Ramesh K.
中科院分区：
文献类型：
--
作者：
Krishnan, S. Shunmuga;Sitaraman, Ramesh K.
通过互联网分发视频正在彻底改变媒体的消费和货币化方式。媒体和视频订阅服务等内容提供商希望确保他们的视频不会失败，快速启动，并且不间断地播放。作为对视频流质量投资的回报，内容提供商期望更少的观众放弃，更多的观众参与，以及更大比例的回头客，从而带来更大的收入。对于内容提供商或内容分发网络（CDN）来说，关键问题是视频质量的变化是否以及在多大程度上会导致观众行为的变化。我们的工作是第一个建立视频质量和观众行为之间的因果关系，超越了纯粹的相关性研究。为了建立因果关系，我们使用准实验设计，这是一种改编自医学和社会科学的新技术。我们以科学的数据驱动方式研究视频流质量对观众行为的影响，方法是使用Akamai流媒体网络的大量跟踪数据，其中包括来自670万独立观众的2300万次观看。我们发现，观众开始放弃一个视频，如果它需要超过2秒启动，与1秒的每一个增量延迟导致5.8%的放弃率增加。此外，我们表明，适量的中断可以减少观众的平均播放时间的显着金额。经历等于视频持续时间的1%的重新缓冲延迟的观看者与经历没有重新缓冲的类似观看者相比少播放5%的视频。最后，我们发现，经历过失败的观众是2.32%，不太可能在一周内重访同一网站比类似的观众谁没有经历过失败。
The distribution of videos over the Internet is drastically transforming how media is consumed and monetized. Content providers, such as media outlets and video subscription services, would like to ensure that their videos do not fail, start up quickly, and play without interruptions. In return for their investment in video stream quality, content providers expect less viewer abandonment, more viewer engagement, and a greater fraction of repeat viewers, resulting in greater revenues. The key question for a content provider or a content delivery network (CDN) is whether and to what extent changes in video quality can cause changes in viewer behavior. Our work is the first to establish a causal relationship between video quality and viewer behavior, taking a step beyond purely correlational studies. To establish causality, we use Quasi-Experimental Designs, a novel technique adapted from the medical and social sciences. We study the impact of video stream quality on viewer behavior in a scientific data-driven manner by using extensive traces from Akamai's streaming network that include 23 million views from 6.7 million unique viewers. We show that viewers start to abandon a video if it takes more than 2 s to start up, with each incremental delay of 1 s resulting in a 5.8% increase in the abandonment rate. Furthermore, we show that a moderate amount of interruptions can decrease the average play time of a viewer by a significant amount. A viewer who experiences a rebuffer delay equal to 1% of the video duration plays 5% less of the video in comparison to a similar viewer who experienced no rebuffering. Finally, we show that a viewer who experienced failure is 2.32% less likely to revisit the same site within a week than a similar viewer who did not experience a failure.