在线视频流质量影响观赏者的行为

时间：2012-11-14 05:28:06

（单词翻译:单击）

It may seem like common sense that the quality of online video streaming affects how willing viewers are to watch videos at a website. But until computer science researcher Ramesh Sitaraman at the University of Massachusetts Amherst and collaborators at Akamai developed a way to rigorously study the question, no one had been able to scientifically test the assumption. They conducted the first large-scale study of its kind to quantitatively1 demonstrate how video stream quality causes changes in viewer behavior. "Video stream quality is a very big topic of interest," says Sitaraman. "Anyone who provides online video content, from the major news channels to sports and movie outlets2, is worried about such things as do videos fail, how fast a video starts up, does it freeze, and how such loss of quality affects viewers."

 
"You want viewers to not abandon your content. You want them to watch longer, and return to your site often to watch more videos, resulting in more opportunities to show ads and to increase your subscriber3 base. The link between video streaming quality and viewer behavior has long been recognized as hugely important, but we couldn't study it with any scientific precision until now."
 
"The ability to collect large amounts of relevant data, plus new techniques we developed for the analysis were the game changers," says Sitaraman, who is also an Akamai Fellow. More than a dozen years ago, he helped build the Akamai network and helped pioneer content delivery network technology now used to stream a large fraction of the online videos on the Internet today.
 
This week in Boston, he presents research done in collaboration4 with S. Shunmuga Krishnan at the Association for Computing5 Machinery6 (ACM) Internet Measurement Conference in a talk titled, "Video Stream Quality Impacts Viewer Behavior: Inferring Causality using Quasi-Experimental Designs."
 
They report that viewers begin to abandon if the video does not start up within two seconds. Beyond two seconds, every additional one-second delay resulted in roughly a 5.8 percent increase in the abandonment rate. They also found that viewers are less tolerant of startup delay for short videos such as news clips compared to longer ones such as movies. Also of interest is that viewers with better connectivity are less patient and will abandon a slow-starting video sooner, while mobile users have significantly more patience than others.
 
Sitaraman also says viewers watch fewer minutes of the video if the video "freezes" while playing. A typical viewer whose video froze for 1 percent of its duration watched for 5 percent fewer minutes than a similar viewer whose video played smoothly7 without freezes. Further, viewers who experienced failures were less likely to return to the same web site to play more videos. A typical viewer who left the site after failing to play a video was 2.3 percent less likely to return to the same site within the week compared to a similar viewer who experienced no failures.
 
This study analyzes8 an unprecedented9 6.7 million unique viewers from around the world who in aggregate10 watched 23 million videos for 216 million minutes over a period of 10 days. To conduct this research, Sitaraman and colleagues used a method more familiar to medical and social science research than to computer systems research. Through the collaboration with Akamai that currently delivers 15 to 30 percent of global web traffic, the researchers had access to millions of anonymous11 traces that contain information of how users watch videos and the quality they experienced.

分享到：


点击收听单词发音收听单词发音  

1 quantitatively 4b081280983d0e01c866e9065e0034b0     
adv.数量上
参考例句：
  • With the ease, radiation detectors can be used semi-quantitatively in the field. 使用射线探测器可以很方便地进行野外半定量测定。 来自辞典例句
  • In other words, you are to analyze them quantitatively and qualitatively. 换句话说，你们要对它们进行量和质的分析。 来自辞典例句
2 outlets a899f2669c499f26df428cf3d18a06c3     
n.出口( outlet的名词复数 )；经销店；插座；廉价经销店
参考例句：
  • The dumping of foreign cotton blocked outlets for locally grown cotton. 外国棉花的倾销阻滞了当地生产的棉花的销路。 来自《简明英汉词典》
  • They must find outlets for their products. 他们必须为自己的产品寻找出路。 来自《现代汉英综合大词典》
3 subscriber 9hNzJK     
n.用户，订户；（慈善机关等的）定期捐款者；预约者；签署者
参考例句：
  • The subscriber to a government loan has got higher interest than savings. 公债认购者获得高于储蓄的利息。 来自辞典例句
  • Who is the subscriber of that motto? 谁是那条座右铭的签字者？ 来自辞典例句
4 collaboration bW7yD     
n.合作，协作；勾结
参考例句：
  • The two companies are working in close collaboration each other.这两家公司密切合作。
  • He was shot for collaboration with the enemy.他因通敌而被枪毙了。
5 computing tvBzxs     
n.计算
参考例句：
  • to work in computing 从事信息处理
  • Back in the dark ages of computing, in about 1980, they started a software company. 早在计算机尚未普及的时代（约1980年），他们就创办了软件公司。
6 machinery CAdxb     
n.(总称)机械，机器；机构
参考例句：
  • Has the machinery been put up ready for the broadcast?广播器材安装完毕了吗？
  • Machinery ought to be well maintained all the time.机器应该随时注意维护。
7 smoothly iiUzLG     
adv.平滑地，顺利地，流利地，流畅地
参考例句：
  • The workmen are very cooperative,so the work goes on smoothly.工人们十分合作，所以工作进展顺利。
  • Just change one or two words and the sentence will read smoothly.这句话只要动一两个字就顺了。
8 analyzes e2e80b8320e1dd8d4c035d41fd7e44e5     
v.分析( analyze的第三人称单数 )；分解；解释；对…进行心理分析
参考例句：
  • This approach analyzes management by studying experience usually through cases. 这个学派通常从实例获得经验，用以分析管理。 来自辞典例句
  • The econometrician analyzes statistical data. 经济计量学者要分析统计材料。 来自辞典例句
9 unprecedented 7gSyJ     
adj.无前例的，新奇的
参考例句：
  • The air crash caused an unprecedented number of deaths.这次空难的死亡人数是空前的。
  • A flood of this sort is really unprecedented.这样大的洪水真是十年九不遇。
10 aggregate cKOyE     
adj.总计的，集合的；n.总数；v.合计；集合
参考例句：
  • The football team had a low goal aggregate last season.这支足球队上个赛季的进球总数很少。
  • The money collected will aggregate a thousand dollars.进帐总额将达一千美元。
11 anonymous lM2yp     
adj.无名的；匿名的；无特色的
参考例句：
  • Sending anonymous letters is a cowardly act.寄匿名信是懦夫的行为。
  • The author wishes to remain anonymous.作者希望姓名不公开。

©2005-2010英文阅读网